I configured Adguard now as the ipv6 dns server in the fritzbox as well. For now it seems to work, under settings > network & internet > network details for my home network it shows the right dns addresses now.
Thanks!
I disabled private dns and it seemed to work yesterday, but today i can not connect to my services again.
Any other ideas on how to pin down the issue?
I found that the cname record seemed to be the problem. Here someone had the same issue.
After changing now to a wildcard A record pointing to the tailscale ip, it all magically works.
Thanks for all the answers!
Well the local LLM is definitely a stretch goal of mine hahahah