This is the way! I’m using it too with a piped instance. Also configured the RSS feed to a Slack channel with yattee://watch?v={videoId} which works awesome. When I press the link, when a new video is posted, it opens in Yattee. Basically I have a privacy focused YouTube with no ads and with subscriptions.
There were many meetings with Autodesk about this. Unfortunately, I didn’t attend these. I believe it had something to do with a subnet change in the internal network. So the license server wouldn’t recognize the new endpoints. However, since yours is unlicensed I’m not sure if this would help you. Have you tried disconnecting from the internet completely? Does that make a difference?
I think your best bets are blocking a process (started from a file) or a network route. For the latter you can try WireShark to monitor every network route.
I still need to de-Google my Shield. How’s the performance of LineageOS on the Shield? HDR and DV content still playing well?
Funnily enough we got this message even in enterprise environment, where licenses were paid (and damn they are expensive). I’m convinced it’s just some process in the software itself. Have you tried looking through every process? Gotta find that one file that starts this pop-up and block it. I think that’s why your firewall rule didn’t help.