I remember running into the same issue a few months ago. I believe the culprit was the “Core” or “Desk” module in the Allowed Module section of the User doctype.
The Users all have Core and Desk modules checked in their profiles. I even added Website to the profile and it doesn’t fix it.
The problem is even more nefarious than I originally thought.
The first time the user logs into the system they have the “Home” designation at the top of the screen, but the first time they leave that to go to some other module, they can never get back to Home.
So here is an example of the User “TR” logging in for the first time. His Desk clearly shows “Home” in the upper left corner, but Home does not appear as a Module in the list below it.
Then the user accesses some other part of the system and tries to return to “Home” by clicking on the blue “E” icon in the upper left corner and they wind up in the Accounting Module!!! (because Home is not in the module list).
It was my fault, I remembered it being ether Core, or Desk module. I tested on my instance and the “Setup” module is the correct module to have enabled.
That is the correct module to set. Strangely enough though, I can only seem to set the modules for users when logged in as Administrator (even though I have System Manager role for myself).
Thank you!