Manually added compilers from Android NDK are forgotten

If I add a new compiler, by going through "Preference -> Build & Run -> Compilers", and for example by selecting "Android GCC (C, arm-4.9)" and clicking clone, naming it for example "My GCC", and quitting QtCreator, this compiler is added to ~/.config/QtProject/qtcreator/toolchains.xml. However, next time I start QtCreator, this compiler is not available any more in the list in "Preference -> Build & Run -> Compilers". Moreover, if I do changes in the compiler configuration (for instance using another version of Android GCC) the new one is not used when building the project, even without restart.

This problem does happen with different flavours of Android GCC compilers (including x86_64), but does not happen if I clone a local compiler in /usr/bin (either gcc or clang) or the clang from the ios toolchain, so it seems to be linked to Android.