Question about setting up game in BHDTS

[Ronin76]

Hi all,
It has been an extremely long time since I have played bhd and am trying to set up an online server for friends to access that are in quarantine. I have downloaded the hearbeatdll file and installed and opened up the udp port to allow players to enter. My friends can see my game but can't enter. The game keeps freezing up on them. Does anyone know what I might be doing wrong?