I'm using Ubuntu 16.04 with gnome, and I'm having scaling problems with some QT applications (VLC, TexStudio). I use a HiDPi external screen and when I disconnect my laptop from the external screen, the icons and fonts become big and pixalated (images below). There is no problem when I'm connected to the external screen, the issue is on the laptop when I unplug it.
I have tried to set QT_AUTO_SCREEN_SCALE_FACTOR, and QT_SCREEN_SCALE_FACTORS variables but nothing works for now.
If any one had the same issue or is familiar with the problem, I would appreciate the help.