lets say I have two on-premise domains (DomainA.org, domainB.org) and one tenant (domainA.onmicrosoft.com). Both domains are sync thanks to Azure AD Connect, so user from domainA can log to office.com, there is no problem. Hoever user from domainB getting this "Error validating credentials due to invalid username or password.", and when I changed password from portal.office.com for this user from domainB. I can log with this new password, but only to office365 services, its not sync to On-prem.
And another wierd thing is, that I cant change password for users from domainA.
Do You know where the problem is?