Network topography can cause an issue sometimes. Are all your computers on the same subnet of your network?
a bad .pem file on the computer where you can't see the hosted files can be an issue:
If none of that works, you may want to click on the FM Server Forum Tab and re-post your question there.
All my computers on the same subnet. I have tried everything to solve this problem. At the end, as you said, the bad .pem file. I was overwright those files and it works.