I think I’m seeing this (or something much like it) while working with Enhanced Input in 5.1.0… I save the input action and all is well until I restart the editor. Then the config is gone. I did this a few times, it continues to inexplicably disappear / get deleted.
This is very troubling, especially since the prototype is just beginning and we cannot proceed with UE unless this is resolved.
GOOD NEWS
I may have found a pattern and a way to prevent this, at least for my case. I have a C++ project, not BP. If you close the project entirely and then build / launch from Visual (which automatically opens the UE editor) then this disappearing info seems to be permanently resolved. After doing this once, you no longer even need to launch this way, you can open the project through the editor and the data is there.
I don’t understand UE well enough to know how this could be possible, but this method prevents the problem we were hitting.