External monitor flicker / signal loss I have a Samsung 28" U28E590 4K Display and a 13" MacBook Pro with Touch Bar (Intel Iris 550 1536 MB Graphics). I have a dongle for HDMI output.

The problem is that the external monitor flickers, displays white noise and sometimes cuts out completely. I've tried SMC reset and buying a new HDMI cable, but the issue persists.

How do I resolve the issue?
I've had a support case at Apple for over a year about this issue. They finally answered that it's a software issue and they are looking into it.
We have spent a lot of money in our business on original adapters and good technics to have a good setup. Several of our MBPs with USB have this flickering problem on 1 of the 2 screens (always the screen you attached last).
I really hope that Apple can find this seriously soon or they will probably lose more customers. We are not very satisfied. After all, we have spent lots of money at Apple to get this sorted with no result more than an answer 1 year after - the answer &quot;it's an Apple software problem&quot;.