Hello. Had the same problem with Ubuntu 19 and OOTB AMD drivers.
Solved it with installing the latest drivers from PPA (not from AMD site - so far it has drivers for Ubuntu 18 only and it did not install well, had to remove them with amdgpu-uninstall).
The correct way to install latest AMD drivers from PPA:
sudo add-apt-repository ppa:oibaf/graphics-drivers
sudo apt-get update
sudo apt upgrade