Python is occupying Jellyfin(8096) port

I have ubuntu server with Docker installed and some containers in it. Recently I noticed that Jellyfin had some problems with running. After reinstalling it like 5 times I noticed it cannot start because of an occupied port. So I tried to get as much info as possible about this process.

First commandsudo lsof -i :8096:

COMMAND  PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAMEmass    1430 root   17u  IPv6  28191      0t0  TCP *:8096 (LISTEN)mass    1430 root   19u  IPv4  28192      0t0  TCP *:8096 (LISTEN)

Thanps -Flww -p 1430

F S UID          PID    PPID  C PRI  NI ADDR SZ WCHAN    RSS PSR STIME TTY          TIME CMD4 S root        1430    1204  0  80   0 - 265524 -     67608   3 Mar26 ?        00:22:57 /usr/local/bin/python /usr/local/bin/mass --config /data

I have no idea what this thing is, and it is very possible that I accidentally installed it while messing with linux. What is this process and how can I get rid of it?