APK won't build in a subdirs template as main .pro file

I have a project where my main pro file is one with subdirs as template. Nothing wrong with that so far. It's becoming incredibly frequent that if I make tiny changes in the settings related, for example, choosing gradle or making small changes in the .pro files subprojects QtCreator gets amnesia and starts saying it cannot build the apk or it cannot find the JSON file.

Whether it's the build tool or QtCreator in general I leave it to you guys.

Now onto reproducing this bug. It's really slippery to pinpoint it but I finally managed to reproduce it.

Suppose you have a project where your main template is a subdirs one. (I will provide those said two projects attached). You will open it, compile it, and close it again. You will open the other project, compile it and close it again. Keep doing the same thing and eventually you will run into the bug, usually it doesn't take long.

To those who don't have the time to try it out I prepared a video.

https://www.youtube.com/watch?v=fSesBz-HXR4&feature=youtu.be

Apologies for the long text. I wasn't even sure where to begin explaining since it's somewhat a weird bug.

I don't know if this is a Linux-only bug or if it happens in Windows and OSX.