Bost I've checked your FreeFlarum forum, and the following error was logged:
flarum.ERROR: ErrorException: [VAPID] Public key should be 65 bytes long when decoded.
In order to fix this, please go to Administration > Extensions > Progressive Web App and click on "Reset VAPID keys". I have never been able to figure out what exactly causes this issue at FreeFlarum, unfortunately. Maybe I should have a look into it again someday...
clarkwinkelmann I believe FreeFlarum has a section in their management panel to access the logs.
Thanks for the response Clark, and yes, that is correct, all Flarum related logs are available at https://freeflarum.com/settings/forum_settings under "View Flarum logs", however this is subject to change in the future