[Bug] Number of visits drop after upgrading to Matomo 5

[enual]

What happened?

Some customers are reporting that the number of visits drop almost in half after upgrading to Matomo 5.

What should happen?

There should be a bug fix in Matomo5 that prevents some potentially duplicate visits. However, it should not atleast lower the number of visits significatnly.

How can this be reproduced?

Upgrading from Matomo 4 to Matomo 5.

Matomo version

5.0.1

PHP version

8.2

Server operating system

No response

What browsers are you seeing the problem on?

No response

Computer operating system

No response

Relevant log output

No response

Validations

• [X] Read our Contributing Guidelines.
• [X] Follow our Security Policy.
• [X] Check that there isn't already an issue that reports the same bug to avoid creating duplicates.
• [X] The provided steps to reproduce is a minimal reproducible of the Bug.

[bx80]

Hi @enual,

Thanks for reporting this, but without more detailed information it's not going to be possible for us to properly investigate this.

Can you provide details of one specific case? Was the drop-off for visits or unique visitors? What plugins are being used? Which exact reports are showing the drop-off? Are campaigns being used?

There are a lot of potential reasons that traffic can change, the more information we have the more likely we can pinpoint the cause.

[gbgcom]

Hi @bx80. The case is regarding our website goteborg.com.

Since we upgraded from Matomo 4 to 5 (and later 5.0.1,) our visitor count has significantly dropped, and we are experiencing unusually long visit durations (around 12 min - very unlikely). While I believe the page views may be accurate, it seems that all other metrics are incorrect. Visitors, entry pages, exit pages, acquisition, to mention a few.

I came across this discussion: https://forum.matomo.org/t/changed-measurement-results-after-upgrade-to-matomo-5/54605/2, and it describes a similar issue.

We recently updated node.js, Debian and php. Node v18.19.0 PHP 8.2 Debian 12

These are the plugins we use: Actions (Core) Annotations (Core) Contents (Core) CustomDimensions (Core) CustomJsTracker (Core) Dashboard (Core) DevicePlugins (Core) DevicesDetection (Core) Diagnostics (Core) Ecommerce (Core) Events (Core) Feedback (Core) GeoIp2 (Core) Settings Goals (Core) Heartbeat (Core) ImageGraph (Core) Insights (Core) IntranetMeasurable (Core) JsTrackerInstallCheck (Core) Live (Core) Settings Login (Core) Settings Marketplace (Core) MobileMessaging (Core) Monolog (Core) MultiSites (Core) Overlay (Core) PagePerformance (Core) PrivacyManager (Core) Settings ProfessionalServices (Core) Referrers (Core) Resolution (Core) RssWidget (Core) SEO (Core) ScheduledReports (Core) SegmentEditor (Core) Tour (Core) Transitions (Core) TwoFactorAuth (Core) Settings UserCountry (Core) UserCountryMap (Core) UserId (Core) UserLanguage (Core) VisitFrequency (Core) VisitTime (Core) VisitorInterest (Core) VisitsSummary (Core) Widgetize (Core)

Inactive plugins:

I've checked all campaigns driving traffic to the website, and they are not the issue.

/Stina

[peterbo]

This is more likely to be caused by the implementation / caching / consent. There is no evidence (yet), that an update might lead to a lower visits count.

Did you check:

• your consent implementation?
• Caching settings / Varnish
• Nuxt / Matomo implementation
• Did anything change in vue router / other updates to the platform?
• Any other changes done around 18th or 19th of december?

It's hard to tell, when exactly this problem arises, because christmas traffic is always not comparable to "normal" traffic patterns. When exactly was the Matomo Update done?

[PeterSchumacher22]

The same type of bug encountered on our matomo installation:

Matomo-Version: 5.0.1 PHP-Version: 8.1.26

Visitors blue line, other line are page impressions.

Visitors droped to half or third, the more visitors a page has, the more drop occured. Page impressions are still the same, but we can see in visitor log these patterns:

Some "unique" visitors are on the page for several hours having lots of PI's. It looks like users with the same client and browser combination are tracked as one visitor.

Example visitor:

Maybe it depends on the settings, we are using cookieless version of the js snippet on our websites. Also IP's will be cut after the second number 123.123.x.x. We don't use any costum plugins.

[bx80]

Thanks for the extra info @PeterSchumacher22, just looking for any configuration patterns here, do you have browser feature detection disabled?

[PeterSchumacher22]

@bx80 no doesn't look like it's disabled, my complete snippet:

<script type="text/javascript" defer> var _paq = window._paq || []; /* tracker methods like "setCustomDimension" should be called before "trackPageView" */
    _paq.push(["disableCookies"]);
    _paq.push(['trackPageView']);
    _paq.push(['enableLinkTracking']);
    (function () {
        var u = "//xxx/";
        _paq.push(['setTrackerUrl', u + 'matomo.php']);
        _paq.push(['setSiteId', '1']);
        var d = document, g = d.createElement('script'), s = d.getElementsByTagName('script')[0];
        g.type = 'text/javascript';
        g.async = true;
        g.defer = true;
        g.src = u + 'matomo.js';
        s.parentNode.insertBefore(g, s);
    })();</script>

[PeterSchumacher22]

So on my installation everything works fine again, I found out, that my hoster moved my installation to a new server but routed the traffic through a reverse proxy. I changed my DNS settings to the new IP adress and everything works again.

[bx80]

@PeterSchumacher22 Thanks for letting us know, good to hear things are working for you now :+1:

[virtualize]

We seem to have the same issue. Starting with the day we did the Matomo 5 upgrade, the number of visitors has dropped by more than half, while simultaneously the visit duration raised from 5 to 15 minutes (which seems unrealistically high).

See this chart. We updated Midnight between January 9. and 10. orange: session duration, blue: visitor count

Another curiosity is the duration drop on Feb. 1st, when sent our monthly newsletter, hence the boost in visitors. Usually there's no change in duration, see Dec. 1st / Jan 1st.

Interestingly the average number of visited pages does not seem to be affected. (red: page visits).

So to us this really looks like an issue in Matomo.

We found the Do-not-track setting enabled after the update, but think it was disabled before, although not 100% sure about that. But this would not explain the unreasonable high visit duration.

@gbgcom @enual did you found any hints?

[peterbo]

From which Matomo version did you update? Are you using the user id feature?

[virtualize]

@peterbo Thanks for the fast response.

From which Matomo version did you update?

Matomo Update History shows: 4.15.1,4.14.2. We updated directly to 5.0.1

Are you using the user id feature?

Not that we're aware of, this is our tracking code

<script>
  var _paq = window._paq = window._paq || [];
  /* tracker methods like "setCustomDimension" should be called before "trackPageView" */
  _paq.push(['trackPageView']);
  _paq.push(['enableLinkTracking']);
  _paq.push(['requireCookieConsent']);
  _paq.push(['setCookieConsentGiven']);
  (function() {
    var u="//metric.xxxxxxx.de/";
    _paq.push(['setTrackerUrl', u+'matomo.php']);
    _paq.push(['setSiteId', '1']);
    var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
    g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s);
  })();
</script>

We do use tracking without cookies and anonymize visitors IP address by 2 bytes and "also use the Anonymized IP addresses when enriching visits" (it's activated).

Please let us know what we can do in helping to pinpoint the issue. Thanks

[peterbo]

Hi @virtualize - looks fine to me. Nothing else was changed on page? On which exact date, the update took place? To debug further, if the update was the culprit of the changes in tracking, I'd have to look directly into your instance.

[virtualize]

I've checked our git log, there are no changes that could impact the tracking. The update to Matomo 5 was done Midnight between January 9. and 10. I will create a user on our Matomo instance and send you the credentials.

[virtualize]

Problem was that our site is behind a load balancer (here: Varnish) and after the update all visitors where tracked with the IP of the load balancer (e.g. 127.0.0.1).

Solved by adding the missing config flags to config/config.ini.php as described here https://matomo.org/faq/how-to-install/faq_98#security-consideration

[General]
assume_secure_protocol = 1
proxy_ip_read_last_in_list = 0 

Thanks @peterbo for helping to resolve the issue quickly.

[MatomoForumNotifications]

This issue has been mentioned on Matomo forums. There might be relevant details there:

https://forum.matomo.org/t/changed-measurement-results-after-upgrade-to-matomo-5/54605/6

[michalkleiner]

Hi @gbgcom, since other people reporting a similar issue here have resolved theirs with making sure the site is not behind a proxy and visits are not attributed to the proxy IP, could you please have a look if this is still an issue for you and, possibly, if adding/adjusting the settings proxy_ip_read_last_in_list = 0 could help?