We have a problem with an app part from an app we developed and is available in the SharePoint store for SharePoint Online. Once in a while, the app part disappears from the page on which it was placed. The app itself and its content lists are still available through 'Site Contents', we just can't select the app part anymore to be placed on a page. This has happened a couple of times over the past year. The solution so far was to delete the app, and restore it from the recycle bin. The app part would then be available to us again, and the content lists would still have their data. Yesterdag, the app part went missing again. so when I tried this workaround again, the restoring of the app from the recycle bin failed. It seems to restore for a couple of seconds, but then it appears in the recycle bin again. I really need the data from the content lists of this app back, so simply reinstalling the app from the store is not the way to go! And furthermore, why does my app part become unavailable for no apparent reason in the first place?
I've seen similar questions on the internet, but none were really answered. Does anyone have an idea about what might be happening?