Unable to insert Form combo box drop down after Microsoft 365 update.

Here is my issue, before I had Microsoft 365 check for updates everything worked fine before that, but after the updates, everything went to hell.
I am no longer able to insert from form drop down combo (I'm not inserting activex) into a cell, the combo is grayed out in developers page.
The file isn't shared, protected or in edit mode.
Trust & display settings are fine.
It won't allow me to even install one on a new blank page when its the first thing I go to do.
I've gotten so annoyed that I uninstalled Microsoft 365, removed registry entries, Downloaded a fresh copy from Microsoft, reinstalled and the problem persists.
I've tried using chatgpt and grok to trouble shoot, went through all their suggested recommendations, but nothing, just a grayed out combo box..

Any help would be appreciated.
Regards.
Michael