Selected columns not greyd out

We have problem with excel on our Azure virtual desktop (W10 Enterprise). We used Excel normaly a few years, but now we have problem with selecting columns. When we select 1-2 columns, than they normaly greyed out. But if we select 3 or more columns, than only first column greyed out.

We have no idea, where could be a problem.

We tried:

quick repair - not working

full repair - not working

Uninstall with Microsoft Support and Recovery Assistant and reinstall with Office deployment tool - It works, but only without M365 account. When we use any of our M365 account, than the problem is back again.

Any ideas?

Thx... T. Kaminsky