My apologies, I misread your account; you're self-hosted, not cloud.
I'm also seeing that behavior.
But that error indicates your server is not allowing the software to communicate with our servers for the update check.
What's puzzling is that the license key check does work, I just did a "refresh" without error.
It's possible that mod security (modsec) is in use and one of its rules blocking the connection.
Is your server using Mod Security, or other security software?
In any case, you would need to check with your host and ask them to check why the connection cannot be made.