Hello, I just replace my GeForce 210 to Radeon RX550 and I use 2 monitors (main monitor is 24" and second monitor is 40"), and I just realized that when I maximize Firefox window there is a white/gray horizontal bar on bottom side of second monitor. I tried with other apps and white/gray bar doesn't appear only on Firefox.

This thing was never happened before when I use GeForce 210. Do you think you can help me out? thank you.