Players connect to a different port when using a VPN

I received the message below from someone on a certain server I host. I don't know if the VPN really is the issue, but since I'm using subdomains for my servers it's not a misinput on his end where he put a different number. So I'm wondering what could have happened here and why he got connected the wrong port Information that may or may not be useful, I don't know : - Hosted on a pterodactyl panel - Subdomains, domain, DNS are made and hosted via cloudflare (not proxied via cloudflare) - Both servers run the same pack with minor exceptions - One of the two servers is on offline mode (not cracked, don't hit me with "admincraft does not support piracy") - Both are using a secondary port used for simple voice chat mod, different for each - All ports used are in the same 25565-25590 range