Login link not sent in new instance

Hi there,
I just installed Klaxon on a Heroku instance, following the README instructions. However, I can not use it. I am facing two issues:
the login link is sent by the Heroku app, but I never find it in my mailbox. I tried work and personal email, no luck. On the SendGrid dashboard, the Requests count is stuck at zero. Here's what's in the logs after I put the user email address:
2021-11-15T14:06:59.976937+00:00 heroku[router]: at=info method=POST path="/login?return_to=https%3A%2F%2Fctxt-klaxon.herokuapp.com%2F" host=ctxt-klaxon.herokuapp.com request_id=c56c8c68-2a93-434f-9fbc-31dd2b924908 fwd="91.200.207.44" dyno=web.1 connect=0ms service=12ms status=200 bytes=5098 protocol=https
2021-11-15T14:07:00.526580+00:00 app[web.1]: [ActiveJob] [ActionMailer::DeliveryJob] [8b1097dd-c54f-40e5-87c3-898de88939be] Delivered mail 619269845cb2_181138c25128@b90c4159-873d-4fb8-8780-adb048898ded.mail (503.8ms)
2021-11-15T14:07:00.526739+00:00 app[web.1]: [ActiveJob] [ActionMailer::DeliveryJob] [8b1097dd-c54f-40e5-87c3-898de88939be] Date: Mon, 15 Nov 2021 14:07:00 +0000
2021-11-15T14:07:00.526740+00:00 app[web.1]: From: social@contexte.com
2021-11-15T14:07:00.526740+00:00 app[web.1]: To: yannguegan@gmail.com
2021-11-15T14:07:00.526740+00:00 app[web.1]: Message-ID: <619269845cb2_181138c25128@b90c4159-873d-4fb8-8780-adb048898ded.mail>
2021-11-15T14:07:00.526741+00:00 app[web.1]: Subject: Log in to Klaxon
2021-11-15T14:07:00.526741+00:00 app[web.1]: Mime-Version: 1.0
2021-11-15T14:07:00.526741+00:00 app[web.1]: Content-Type: multipart/alternative;
2021-11-15T14:07:00.526742+00:00 app[web.1]:  boundary="--==_mimepart_619269845820_181138c250d8";
2021-11-15T14:07:00.526742+00:00 app[web.1]:  charset=UTF-8
2021-11-15T14:07:00.526743+00:00 app[web.1]: Content-Transfer-Encoding: 7bit
2021-11-15T14:07:00.526743+00:00 app[web.1]: 
2021-11-15T14:07:00.526743+00:00 app[web.1]: 
2021-11-15T14:07:00.526743+00:00 app[web.1]: ----==_mimepart_619269845820_181138c250d8
2021-11-15T14:07:00.526743+00:00 app[web.1]: Content-Type: text/plain;
2021-11-15T14:07:00.526744+00:00 app[web.1]:  charset=UTF-8
2021-11-15T14:07:00.526744+00:00 app[web.1]: Content-Transfer-Encoding: 7bit
2021-11-15T14:07:00.526744+00:00 app[web.1]: 
2021-11-15T14:07:00.526744+00:00 app[web.1]: Klaxon
2021-11-15T14:07:00.526744+00:00 app[web.1]: 
2021-11-15T14:07:00.526744+00:00 app[web.1]: Login
2021-11-15T14:07:00.526745+00:00 app[web.1]: -----
2021-11-15T14:07:00.526745+00:00 app[web.1]: 
2021-11-15T14:07:00.526745+00:00 app[web.1]: Thank you for using Klaxon.
2021-11-15T14:07:00.526745+00:00 app[web.1]: 
2021-11-15T14:07:00.526745+00:00 app[web.1]: Go to Dashboard 
2021-11-15T14:07:00.526746+00:00 app[web.1]: ( https://ctxt-klaxon.herokuapp.com/login/token?token=eyJhbGciOiJIUzI1NiJ9.eyJkYXRhIjp7InVzZXJfaWQiOjM0fSwiZXhwIjoxNjM2OTg4ODIwfQ.GxIS4LlYo9vN8FLHocrsoSZov4NgifXoThlPWjwFqHg )
2021-11-15T14:07:00.526746+00:00 app[web.1]: 
2021-11-15T14:07:00.526746+00:00 app[web.1]: 
2021-11-15T14:07:00.526746+00:00 app[web.1]: You're receiving this email because you just tried to log into
2021-11-15T14:07:00.526746+00:00 app[web.1]: your Klaxon account. ( https://newsklaxon.org )
2021-11-15T14:07:00.526747+00:00 app[web.1]: ----==_mimepart_619269845820_181138c250d8
2021-11-15T14:07:00.526747+00:00 app[web.1]: Content-Type: text/html;
2021-11-15T14:07:00.526747+00:00 app[web.1]:  charset=UTF-8
2021-11-15T14:07:00.526747+00:00 app[web.1]: Content-Transfer-Encoding: 7bit
2021-11-15T14:07:00.526747+00:00 app[web.1]: 
2021-11-15T14:07:00.526747+00:00 app[web.1]: <!DOCTYPE html>
2021-11-15T14:07:00.526748+00:00 app[web.1]: <html>
2021-11-15T14:07:00.526748+00:00 app[web.1]: <head>
2021-11-15T14:07:00.526748+00:00 app[web.1]: <meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
2021-11-15T14:07:00.526749+00:00 app[web.1]: 
2021-11-15T14:07:00.526749+00:00 app[web.1]: <style>body {
2021-11-15T14:07:00.526749+00:00 app[web.1]: color: #ff0b3a; padding: 30px; font-family: "Helvetica Neue", Helvetica, sans-serif;
2021-11-15T14:07:00.526749+00:00 app[web.1]: }
2021-11-15T14:07:00.526749+00:00 app[web.1]: .klax-button:hover {
2021-11-15T14:07:00.526749+00:00 app[web.1]: background-color: #ff0b3a; color: #ffffff !important; text-decoration: none;
2021-11-15T14:07:00.526750+00:00 app[web.1]: }
2021-11-15T14:07:00.526750+00:00 app[web.1]: .klax-button:hover a {
2021-11-15T14:07:00.526750+00:00 app[web.1]: background-color: #ff0b3a; color: #ffffff !important; text-decoration: none;
2021-11-15T14:07:00.526750+00:00 app[web.1]: }
2021-11-15T14:07:00.526750+00:00 app[web.1]: </style>
2021-11-15T14:07:00.526751+00:00 app[web.1]: </head>
2021-11-15T14:07:00.526751+00:00 app[web.1]: <body style='color: #ff0b3a; font-family: "Helvetica Neue", Helvetica, sans-serif; padding: 30px;'>
2021-11-15T14:07:00.526751+00:00 app[web.1]: 
2021-11-15T14:07:00.526751+00:00 app[web.1]: <div class="container" style="max-width: 1200px; margin: 0 auto;">
2021-11-15T14:07:00.526752+00:00 app[web.1]:    <div class="klax-app-name" style="padding-bottom: 50px; font-weight: bold; font-size: 18px;">
2021-11-15T14:07:00.526752+00:00 app[web.1]:     Klaxon
2021-11-15T14:07:00.526752+00:00 app[web.1]:   </div>
2021-11-15T14:07:00.526753+00:00 app[web.1]:   <h3 style="border-top-width: 0.2em; border-top-color: #ff0b3a; border-top-style: solid; padding-top: 10px; font-size: 2.25em;">Login</h3>
2021-11-15T14:07:00.526753+00:00 app[web.1]: 
2021-11-15T14:07:00.526753+00:00 app[web.1]:   <p class="klax-lead" style="font-size: 21px; line-height: 1.4; word-wrap: break-word; margin-bottom: 20px; font-weight: 300;">Thank you for using Klaxon.</p>
2021-11-15T14:07:00.526753+00:00 app[web.1]: 
2021-11-15T14:07:00.526755+00:00 app[web.1]:   <p style="font-size: 14px; line-height: 1.4em; word-wrap: break-word;"><a class="klax-button" href="https://ctxt-klaxon.herokuapp.com/login/token?token=eyJhbGciOiJIUzI1NiJ9.eyJkYXRhIjp7InVzZXJfaWQiOjM0fSwiZXhwIjoxNjM2OTg4ODIwfQ.GxIS4LlYo9vN8FLHocrsoSZov4NgifXoThlPWjwFqHg" style="font-size: 18px; line-height: 1.33333; display: block; text-align: center; text-decoration: none !important; color: #ff0b3a; padding: 10px 16px; border: 1px solid #ff0b3a;">Go to Dashboard</a></p>
2021-11-15T14:07:00.526755+00:00 app[web.1]: 
2021-11-15T14:07:00.526756+00:00 app[web.1]:   <p class="klax-fine-print" style="font-size: 12px; line-height: 1.4em; word-wrap: break-word; margin-top: 30px;">You're receiving this email because you just tried to log into your <a href="https://newsklaxon.org" style="color: #ff0b3a;">Klaxon account.</a></p>
2021-11-15T14:07:00.526756+00:00 app[web.1]: </div>
2021-11-15T14:07:00.526756+00:00 app[web.1]: 
2021-11-15T14:07:00.526756+00:00 app[web.1]: 
2021-11-15T14:07:00.526756+00:00 app[web.1]: </body>
2021-11-15T14:07:00.526757+00:00 app[web.1]: </html>
2021-11-15T14:07:00.526757+00:00 app[web.1]: 
2021-11-15T14:07:00.526757+00:00 app[web.1]: ----==_mimepart_619269845820_181138c250d8--
2021-11-15T14:07:00.526757+00:00 app[web.1]: 
2021-11-15T14:07:00.526829+00:00 app[web.1]: [ActiveJob] [ActionMailer::DeliveryJob] [8b1097dd-c54f-40e5-87c3-898de88939be] Performed ActionMailer::DeliveryJob (Job ID: 8b1097dd-c54f-40e5-87c3-898de88939be) from Async(mailers) in 521.73ms
Using the login link found in the logs, I can access my Klaxon account on the instance. I added the bookmarlet, yet when I try to use it, the side panel show the login box again, meaning that the user connexion is not active.
themarshallproject / klaxon

Login link not sent in new instance #510
