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