Keeps changing between low and high brightness

Recently the projector has started to frequently switch between low and high brightness.
I don’t do anything, but it changes to low brightness, then changes back to high brightness a few seconds after.

This normally happens only just after I started or stopped playing something.

But now I tried to watch a soccer game, and it constantly changes back and forth every 10 seconds, making it unwatchable.

Anyone know what’s wrong? I didn’t have this issue before.

I’ve heard of this happening when the external power supply is not supplying enough power at any particular moment. It seems like the projector will ‘fall off’ of the external power when it can’t keep up, then goes back onto the external power seconds later. If this is related to the problem you’re seeing, I couldn’t guess why it happens when it does, but maybe if you’re using a third-party power supply you could try switching to a larger one for a bit.