W10 laptop keeps asking for network login

I have 4 W10 computers
1 desktop 1
2 HP elitebook
3 HP mini
4 desktop 2

all talk to the nas
they all talk via the homegroup

via file explorer - networks:
the mini talks to the desktop 1 and elitebook
the desktop 1 talks to the mini and elitebook
the elitebook will talk to the mini but keeps asking for a login to talk to the desktop 1

I have not brought desktop 2 into this yet.
the desktop 1, mini and elitebook are configured the same under network/advanced
all in the same workgroup
the elitebook has HP client security installed but I can find nothing in there that would cause this.

the the desktop 1 and mini do not ask for a login for any connection.
So why is the elitebook asking for login to the desktop 1 and not the mini?

Don't know why this is so but why not add the desktop credentials to the elitebook?

Many of us have been through these puzzles and I have windows credentials added to my comps whether they need them or not!

Don't forget, the credential username is in the form of computername\username.

Great. Whatever it takes...!!