Failed to connect to api.zoom.us port 443: Connection timed out

Hello,
We haven’t been able to connect to zoom api for two days.
We don’t have any error code. After trying to connect, after some time I get the message:
Failed to connect to api.zoom.us port 443: Connection timed out

It looks like zoom is blocking our server’s IP address. We use LH.PL hosting. We contacted them but they insist that the problem is not on their side.
I’ve read a similar thread

but it wasn’t very useful
Please help.