Can't play Xbox live games online with Ultimate Pass (-1 ms latency and 100% packet loss in...

So ever since the Xbox Beta App came out last year, where I had to update Windows 10 to version 1903, I haven't been able to play Forza or Sea of Thieves online anymore, meaning, I have problems with my connection to Xbox live services.

My connection to teredo was fine, I'd forwarded all necessary ports on my router as described, but I still couldn't get a connection - the Xbox Networking tool in the Windows showed something strange though - whenever I reset my firewall, the first benchmark
shows a normal latency and 0% packet loss, the second benchmark though shows "-1 ms" and 100% packet loss. Therefore I've reduced the problem to something firewall-related.

I've managed this workaround: When I play Forza, I turn my firewall off, start matchmaking for an online lobby, and turn the firewall on while still searching. This allows for the necessary firewall rules to be enabled so teredo will work, but it will
establish a connection before my firewall will block it, and I can connect to a server. It will then play perfectly fine, provide a good online experience, until e.g. the race series is over and I am brought back to free roaming, meaning there's a server switch
and then I will be booted out again.

There is not specific Firewall rule that could be responsible though, I've even reset my Firewall settings, I've also reset my network adapter settings, and I've also run multiple /sfc repairs.

What do I do now?

PS: The "Fix it" button below does not fix my problem.

Benchmark with firewall turned off: https://i.gyazo.com/74b4c321f54f4709832c42e4cd078cf7.png
First benchmark after firewall reset: https://gyazo.com/c84d1a5fd6595b26ea03fdeefe85d585
Second benchmark after firewall reset: https://i.gyazo.com/691460570ca025983496197de7fe9223.png
Teredo state: https://i.gyazo.com/2346e921183f4d7eb278c7f092a56165.png

:)