Broken bind mount access for Syn&QTS even with PGID=0, PUID=0, 
MUMBLE_GID=0, MUMBLE_UID=0, /data:770 (normally 660) and owned (docker running under UID=0, GID=0, forced requirement). Why is every docker trying to force running as 1000:1000+ when you can let the end user do what they need? So much hand-holding...*sigh* Breaking usability.

/entrypoint.sh: line 77: /data/mumble_server_config.ini: Permission denied