Server says "old"

so ive made a server in 20w19a, and everything works fine, but when someone or even if i try to join, over the connection thing it says old, and it just times everyone out.

I tested it with a 1.15.2 server, and same thing happens, and were all on the same version and everything

my firewalls arent the issue because those are off anyways.

 

heres a log of me tryingto join it and timing me out https://paste.ubuntu.com/p/n7ZgFKFMZ7/