Random/changing high TCP port used by server

[justonce01 2]

I have noticed that the server is listening to a TCP port, not usually mentioned by the guides. It seems that the port is also changing and randomly assigned whenever I restart the server

$ ss -tulpn
Netid    State     Recv-Q     Send-Q                             Local Address:Port          Peer Address:Port    Process                                      
udp      UNCONN    0          0                                        0.0.0.0:12780              0.0.0.0:*        users:(("enfMain",pid=7567,fd=150))         
udp      UNCONN    0          0                                        0.0.0.0:12782              0.0.0.0:*        users:(("enfMain",pid=7567,fd=149))         
udp      UNCONN    0          0                                        0.0.0.0:12784              0.0.0.0:*        users:(("enfMain",pid=7567,fd=167))                 
tcp      LISTEN    0          128                                    127.0.0.1:43465              0.0.0.0:*        users:(("enfMain",pid=7567,fd=162))   

In the case above, it's 43465 TCP. What is this port used for and is there a way to set it statically?

The server is working fine without allowing it in my firewall/forwarding in the router, but I'm still curious. Since it's always a different one, it's hard to look for existing posts on this forum about it or the internet.