I'm not 100% sure this is related to my issue but it's a similar end result. I'm running on Ubuntu 21.04 (aware it's not listed as supported, didn't realize when I updated the system, but never ran into any issues till this)
When I update all three parts everything works for about 5 minutes then I'm unable to access the admin panel. As soon as I roll the core back to the current release (leaving FTL and Web on the dev branch) everything goes back to normal and I can access everything again.
Crucially though it does not stop functionality outside of the admin panel and the API. Ads are still blocked and dns resolution still functions but I'm unable to monitor or edit anything till I roll Core back to the non beta version.
If this should be separated please let me know and I'll repost as it's own.