I have auto-publishing turned off. I have seen other posts about app changes being lost when using manual publishing.
I have experienced it from time-to-time, but could never know when it happened, and it was only recently that I made the connection between the losses and manual publishing. I would just see a feature in my app wasn’t working, and find custom actions missing or only partially there.
Today it happened while I was sitting here. I had a custom action that did nothing but go to a detail screen. Today I needed to add some conditions to it, so I did. I then published the app. It was such a small change I thought nothing of it.
Then I was just testing, and wanted to tweak the custom action, and it was gone. There was just the normal default action there.
Changes I made in the data editor (columns added, including an ITE column) were unaffected.
This has been going on since before the “undo” action was introduced. Not sure if those two things are related.