A Windows 11 VM that I manage went through an update cycle and, when it was finally finished, the bottom bar was missing.
Like just about all Windows issues, I had to spend a long time googling solutions and trying them, before I eventually landed on the correct solution. I tend to avoid those tiresome Youtube videos that take 10 minutes to tell you that: 1. Their solution is simple and will work, 2, don't forget to subscribe, while failing to acknowledge that there might be other causes for the failure that you have experienced.
Surprisingly, the solution came in an AI answer with the right set of search terms. In my experience, the hit rate for accuracy of AI searches is poor, but this time, it worked!