Small update here. I was performing this all under a Teams subscription. I assumed that might have been the case so I went ahead and got a personal trial to isntall the apps since just updating them from my Teams account still seemed to work fine. Interestingly when I went back to my corporate account, the old interface (with the sidebar) returned and there was a new "Beta" tab which I had never seen before. Issue seems to be fixed as I can now access the Beta apps again.