Problem: Users are unable to MFA login to the Windows machines
Cause: User added a Connector for a NEW NON Prod On-Prem PAM installation in a Child Domain since the tenant URL was not set in the Production Zones which caused this issue as it now saw two connectors with different tenant URL's.
Resolution: Please use the local admin account to run dzflush and then dzrefresh to rebuild the cache in order to login with MFA successfully.