Evidently it must be your host considering it works on my website and we are using the same version. Check if they can traceroute to your IP and port. Remember they need to unblock both UDP and TCP out. Also ask them to unblock these ports ranges. If this doesn't work I can get into a teams/discord call with you.
TCP: 27015-27030, 27036-27037
UDP: 4380, 27000-27031, 27036