Hi, In my case i have an r9 380x and i have the SAME problem as yours.
I tried fresh installing it with DDU but same thing is happening just as your describe.
This problem happens with 2 indie games I have installed (the messenger and wizard of legend), however, if I play CS:GO and Killing Floor 2, for example, I can play them perfectly without problems.
EDIT: In my case, disabling Freesync of each game (the messenger and wizard of legend) on the radeon software "fixed" the problem and now i can play those games without problems.
I've atached an image so you can see what i did.