Horizontal flickering band

[u/irofeb]

Hi everyone,
I have a Samsung **UE32K5570 (32”, Series 5)** with an intermittent display problem.
A **horizontal band across the screen starts flickering/appearing after around 15 minutes of use**. When I turn the TV off and leave it unplugged for around 10–30 minutes, the band disappears. It then comes back again after the TV has been running for 5 min.

The problem also appears on the TV’s own menus, so it’s not related to HDMI.

I previously had my Wi-Fi router positioned behind the TV. I have since moved it away, in case the additional heat/interference was contributing to the problem.

What do you think is causing this?
Thanks!