Unable to access this computer over the network. Insufficient permissions

Question

Hi Community,

The computer affected by the error is the following:

In my local area network consisting of (1) Desktop, (2) Laptop and (1) NAS answering wrong two or three times to Laptop-1 asking me for the network password (network credentials), it so happened that now I get presents the above error in the File Manager of the same Laptop-1, when I try to access the network resources of both Desktop and Laptop-2 from the "Network" folder.

The router sees the network without problems, the other two computers access from File Manager/Network without errors each other and Laptop-1 and I can map without problem

However, Laptop-1 sees the other two computers on the network and the NAS with both the "ping" and the mapping and, through it, it is possible to reach both Desktop and Laptop-2, as shown in the following screenshot:

So, I'm assuming the error is confined to just Laptop-1 and File Manager in some way. To try to fix it, I applied the Wiki articles "Networked PCs windows 10 1803 and later" and "Resetting network and Internet connections" to Laptop-1, but to no avail.

I've searched online and, in the community, to find a case like mine, but I haven't been able to. (Note: I must however add that the error is not fixed but volatile, sometimes the network folder shows the network components correctly accessible and sometimes not.)

If anyone can help me resolve this unfortunate situation, I will be grateful.

Vittorio