@jared
In my opinion there is no problem that is directly effecting the Signal 6 issue in iOS.
The actual problem is the app contains ads and the ads ID/Key is not saved in the project settings.
The main issue which is remained UNSOLVED is the ability to save the project settings as not all of it is saved.
However, for the time being just remember to supply the settings before publishing the app to avoid this issue from coming up.
The issue of some settings are not retained after closing the design page remains unsolved and once solved the user will not see the Signal 6 issue so if the developers in Thunkable solve this issue many users will feel relaxed.