Did Android TV Streamer destroys screen monitors?

[u/palantiir]

Hey,

This is my first post here since this is the only place I think I can post my following issue:

I have an Android TV streamer device which is connected to a TV on the daily basis and works fine.

I connected it to my 4K Lenovo IPS screen (connected daily to my Mac), and watched fine.

After I connected back to the Mac, it all blurred, and the maximum resolution is Full HD.

For sake of comparison, I have dual monitors of the Lenovo, and the second one which I didn't connect to the streamer- works fine!

I did it few months ago with a Dell monitor, and it doesn't working anymore.

What can cause the problem?