I have had trouble with this monitor from day 1. It's running at 4k resolution via Displayport. It will occasionally suffer a flicker / flash band across the screen, often accompanied by a click from the speakers. It can be quite rare, perhaps once or twice an hour, other times it's very frequent, several times a minute.
I've tried dropping the resolution to no effect. (The same computer was used with a lower resolution monitor for months, so I know the computer isn't to blame). It's making the monitor completely unusable and I just need it replaced or I'll have to dump it.
The seller (Ebuyer) tell me to contact Acer. But Acer's website won't do anything without the serial number, and I can't possibly read that because it's tiny and printed inside the back of the stand which doesn't come off!
I really hate this monitor, it's been a huge waste of time and money and I feel like there's no support.
(I do have a replacement Displayport cable on order and will try that, unlikely though it is).
Colin