This happened to us a few weeks ago. For us, it was because the connectors updated and ExchangeOnlineManagement module was updated to an unsupported version as part of the update
On your connector system run a Get-InstalledModule command (Ours had been updated to 3.1.0)
If you are currently above 2.0.5 it may be the cause of the failure
Uninstall PowerShell Module for Specific Version
Uninstall-Module -Name ExchangeOnlineManagement -RequiredVersion 3.1.0
Install OLD PowerShell Module with Specific Version
Install-Module -Name ExchangeOnlineManagement -RequiredVersion 2.0.5
As soon as we changed the installed version, our powershell was able to connect to exchange. These instructions came from our SR with VMware
