[REG 4.12->4.13] QtCreator keeps parsing qmake project

Since updating QtCreator to version 4.13.0, all qmake based projects are constantly being reparsed (the progress bar in the lower right corner pops up every ~5 seconds with "reading project <project_name>")

This is only with qmake projects, cmake doesn't do that.

I've already removed the build dir and the *.pro.user file, but that doesn't have any effect.

This is very annoying as it also makes following symbols in the source code not working.