Some people can't join my gameserver

I am hosting a gameserver for the game: SCP:SL.
I can’t port-forward 7777 UDP on my router because of personal reasons.

That’s why I am using this software. I downloaded the software for my laptop I am using as the server. When the server is running, I have the tunnel running as well. In my firewall, I have tje port 7777 open.

Now the thing is. My server needs to undergo a verification process so that it will be visible in the public server list. Verification team, however, cannot connect to my server as of which it can’t be verified.

Yesterday, I was sitting with 2 support members of SCP:SL with another random guy in my server. They had ~100ms Ping, but they were able to connect. The verification team couldn’t after 30 minutes of different solution attempts. Now. I still don’t know what the issue is.

Some ppl. can connect, some cannot.

I would really appreciate any help.