Netflix mid-roll ads not blocked

Prerequisites

[X] I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
[X] This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
[X] This is not a support issue or a question. For support, questions, or help, visit /r/uBlockOrigin.
[X] I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
[X] The issue is not present after disabling uBO in the browser.
[X] I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

[X] uBO is the only extension.
[X] uBO uses default lists and settings.
[X] using a new, unmodified browser profile.

Description

On the Netflix with ads plan, uBlock only sometimes blocks midroll ads. This behavior is the same on Librewolf (Flathub flatpak) and Firefox (Fedora rpm). The ads usually don't play if you skip right to them but usually do if you watch the episode normally. If the webpage is reloaded, playback resumes about where you left off; and the ad is usually skipped.

A specific URL where the issue occurs.

happened on many episodes, example: https://www.netflix.com/watch/80095340
(https://www.justwatch.com/us/tv-show/castlevania suggests that this is only available on the ads plan in some countries.)

Steps to Reproduce

Have a Netflix account with the ads plan.
Watch an episode.
The pre-roll ad gets blocked, but the mid-roll ad(s) usually don't. (Mid-roll ads are marked in the timeline with orange highlighting.)

Expected behavior

Mid-roll ads would be skipped when watching content normally.

Actual behavior

Most mid-roll ads are not skipped when watching content normally.

uBO version

1.56.0

Browser name and version

Firefox 123.0.1 (Fedora rpm) & Librewolf 122.0.1-2 (Flathub flatpak)

Operating System and version

Fedora 39 Workstation Edition

uBlockOrigin / uBlock-issues