Windows not accepting my network credentials

Picking up an old thread I know but I had the same problem and had tried all the suggestions above without success - but the solution below worked:

Situation - small home network, one laptop that was upgraded to Win 11 Pro a few months ago, I am the only user and one newly built desktop PC, Win 11 Pro, I am the only user of that too. When trying to access correctly shared files either way, I got the error message 'user name or password is incorrect' even though I was correctly using my user name and password and tried all the combinations that various web help forums suggest e.g. 

• user name 'XXXXX' where that is the 5 letter abbreviation of my MS login name that is found at C:\users\XXXXX
• computer_name_I_want_to_access\XXXXX
• my_MS_login_name.com

All gave the same message so to narrow the problem down (e.g. firewall, router, sharing error, credentials issue etc) I switched to trying to Remote Desktop between the two computers. I got the same error but this at least ruled out folder sharing as the cause. Then I hit on this idea. Neither computer was actually using my Microsoft password at login in. One was using my Microsoft PIN, the other was using Face Recoginition. What if it was that?

Logged out of the computer I was trying to access via Remote Desktop. Started to log back in BUT clicked on Forgot My PIN - continued to reject other ways of signing in (Passkey etc) until I got back to 'Use Password'. Once I had logged in with my MS password, I could immediately access via Remote Desktop from the other PC. It works with either XXXXX or computer_name_I_want_to_access\XXXXX and has survived several reboots where I went back to using PIN and face recognition. 

Seems to be that when you use PIN or other, non-password methods, even though you may well have connected your PC with your MS account and logged into Office 365 etc, unless you have used your password to physically log into your PC, then it may not have been successfully registered in Credential Manager.