Domain computers when entering a shared folder (on a DC) asks for a password although it should not. Why can this be?

Question

System administration

a computer with a windows server 2012 folder (with ad dns wds roles).
PC windows 7 clients. computers in the domain.
The situation is this.
Not domain win7 and win10 enter the shared folder for 2012.
Freshly planted (day two) computers enter the domain normally.
But if the domain computer stands for two days, then it will no longer enter the shared folder for 2012. But he comes to other shared folders calmly.
On windows 2012, in the windows log in the security section, there are entries that my domain computer (name PC1) tried to log in with the login PC1\user.
Although in theory there should be a guest.
What is the problem?

Answer 1

And what are the rights of the Sher himself? What happens if you relogin to the system with a problematic user, there will be no access?