Happens to me also all the time (100%). Non of the patch that claimed it was fixed fixed it.
All I have to do is restart game.
What game client are you using? Windows
What are your current graphics settings? Maxed, 1920×1080
Are you playing in full screen or windowed mode? window mode
Is your inventory full or maxed out? No
Do you play with bags displayed or hidden? Hidden
Added screenshots before game exit and after game relaunch.
