yes, i am still using TS3 and i have a strange problem with my own little TS3 Server, which is hosted on my snology NAS via docker. I opened the ports 9987, 10011 and 30333, but i cant upload anything as long as i am connected via the subdomain. If i am connected via domain (standard port) or the internal IP the badges and icons are shown and i can upload anything. If i am connected via subdomain (ts.mydoamin.ending) i cant upload and see anything.
So the problem should be the svr for the subdomain.
here is how i config them:
_ ts3 . _ tcp IN SRV 2 5 10011 domain.de.
_ ts3 . _ udp IN SRV 0 5 9987 domain.de.
_ ts3 . _ tcp IN SRV 1 5 30033 domain.de.
(if this works, i will change the ports into random ports to set up the security )
Best regards from germany!