Using Classic Outlook on Windows for personal email, calendar, and contact management
I cannot verify what you have said in your post, Tom.
When I put my Outlook into safe mode, it did not jump. But when I reopened it normally, even with all my add-ins "disabled," it jumped again into the middle of my inbox.
I have just used Revo Uninstaller to do a deep uninstall - and then reinstalled it and rebooted my PC. All of my add-ins are disabled - and (so far) it has not jumped yet (but it has only been 10 minutes). I just might be lucky...
I also don't have grammarly at all (just FYI).