I submitted a ticket to Microsoft, but figured I would see if anyone in the community has experienced anything like this.
We publish a Power Bi app to a group of users and have 1 user that after a little while of it being published, the app disappears from their list, but he still has access to the workspace. They can go to Get apps and grab the app again, but are unable to favorite it. They get an error message when trying to favorite the app and on a page refresh, the app is gone again.
This is the only user that we are seeing experience the issue. I can reproduce it with his account on multiple operating systems and browsers. We unpublished the app, and republished it and it worked for about 2 weeks, and then disappeared on him again. He is able to Favorite other apps we have published and is just a consumer of the data.