The multi-select issue is likely a display inconsistency. In order to avoid problems with updates and multi-select the content pane queues update request until the multi-select is cleared by selecting a single item. 

Administrators as well as any agent assigned to groups in multiple brands, will be able to see tickets in the queue from both brands. To see only one brand in the queue, the agents can select a specific brand from the brand selector at the top of the navigation pane.

I tried everything.

with administrator user works, but with a normal operator the problem persist.

Below an example with an operator user.

See the attached file.problem.jpg

Thanks

We have been unable to replicate that in a test environment. Please open a support ticket to get more personalized assistance.