I've been fighting this issue for 2 days now.
I have a mixed network, 2 win 11 PCs and 2 win10 PCs. One of the Win11 PCs is more or less the file server, all the others access shared drives/folders on this machine. 2 of the three other machines have no problem connecting to the shares, but the other win 11 machine (we'll call it NewPC) suddenly can't. The other machines also cannot connect to shares on that NewPC.
If I had any hair, I'd have pulled it all out by now.
All machines were logging in using an MS account.
No credentials seem to work for this NewPC when trying to access the file server. Not an MS account, not a local account.
However, when I switched to a local account on NewPC, suddenly I can connect to the file server in Network, but only one of the mapped drives actually allows access. ??? How is this possible???
So I tried disconnecting a mapped drive, and remapping it. Nope, doesn't like any credentials I try. And, under credentials manager on the file server, it doesn't even show the credentials for NewPC connected to that mapped drive.
This is utterly insane.