First thing I would do, is in this screen, click on the “Owned by me” option. Do all the apps still show? If so then you definitely need to reach out to AppSheet support.
If they do NOT show, then you are logging in with the wrong Google account which does not have access to the app. You need to use the account that is the owner/App Creator of the apps.
Thanks @WillowMobileSys ! Yes, I checked that and they all still show. I have reached out, but waiting is painful since we live in our app. Any thoughts about the “use secure browsers” in the cell phone screenshot? Any other suggestions to try while I wait for support?