Your logging is probably down

Actually, one thing I want to do is switch from services being on a subdomain to services being on a path.

immich.myserver.com -> myserver.com/immich jellyfin.myserver.com -> myserver.com/jellyfin

I’m getting tired of having to update DNS records every time I want to add a new service.

I guess the tricky part will be making sure the services support this kind of routing…

Why are you having to update your DNS records when you add a new service? Just set up a wildcard A record to send *.myserver.com to the reverse proxy and you never have to touch it again. If your DNS doesn’t let you set wildcard A records, then switch to a better DNS.
Not OP but a lot of people probably use pi-hole which doesn’t support wildcards for some inane reason

It does support it, you just have to add it to dnsmasq. I have it Setup under misc.dnsmasq_lines like so:

address=/proxy.example.com/192.0.0.100 local=/proxy.example.com/

Then I have my proxied service reachable under service.proxy.example.com