Keyboard shortcut problems Qt5

[JohnDoeLD]

I'm currently using SMPlyer (16.4.0-r1) on Gentoo and having issues when compiling with Qt5. Certain keyboard shortcuts, e.g. "]" for speed increase, don't work. It seems the modifier key is not registered correctly. "]" is AltGr+9 on my keyboard layout, but SMPlayer decreases volume, which would be just "9" without the modifier key. I'm not having any issues when compiling with Qt4 instead. Other Qt5 programs don't have the same issue and I've also tried deleting the smplayer.ini, but no change...
Qt versions: 5.5.1 / 4.8.7

[rvm]

SMPlayer sets the shortcuts but then it's up to Qt to detect when a shortcut is pressed and call the action. So I think it's probably a bug in Qt5. In my computer "]" works but the keys from the keypad don't. They work with Qt4.