Tks Saguaros - I much appreciate your efforts.
However, maybe I didn't explain properly what the issue is. I'm writing the following text below for future reference, but for now I just reset the menu items for the pages that do not involve GuruPro so that the correct default template comes up for the great majority of the users.
No action from you is requested at this time. I will let you know when I'm ready to have you looking into it again.
For future reference:
The template for the user group Foster Farms is to be cassiopeia_cassiopeia_for_foster_farms - Default
BUT, everyone one else, which is 99.999% of the users, are to be using the Cassiopeia - Default template.
Here's what happens presently:
USERS BELONGING TO USERGROUP FOSTER FARMS
When users of this group login, they get this page: https://prnt.sc/fPis3IgK6KR1 which is correct, and the menus are working ok.
USERS BELONGING TO ANY OTHER USERGROUP
When users of any other group login, they get to this page: https://prnt.sc/o_AZwhcj3_jmHowever - at first sight all is ok.
HOWEVER, as soon as the user clicks on any of the dashboard menu items, the template is automatically switched to https://prnt.sc/fPis3IgK6KR1 (cassiopeia_cassiopeia_for_foster_farms).