U2720Q, Mac mini M1, flickering

I am faced with similar strange behavior of this monitor connected with j5create > DisplayPort cable adapter to my new Mac mini M1. In one moment two vertical flickering full-height light columns appeared closer to edges. I'm pretty sure it was the backlight itself, not the image. At the same time, colors have changed (washed) in the paspartu-like frame, when the rectangle closer to the monitor center remained colored. I tried to switch to a different input (I have Intel MacBook 2020 connected to USB Type C port with 3rd-party USB Type C > USB Type C cable), the state did not change. I completely turned off the monitor from the power supply and turned it back. Colors became normal across the whole monitor area but it was still flickering. After some time all symptoms completely disappeared without any reason.

I got that one time again, with backlight flickering, no color change but one of an app's windows being closed still blinked as very transparent. Again everything disappeared after some time.

I never had issues with Intel MBP + USB Type C connection so far. Now I connected my Mac mini with Plugable USB Type C > HDMI 2.0 cable adapter and keep watching. I suspect it is j5create cable adapter but how it can affect the backlight? It even does not send any power to the monitor. I didn't have issues with it on the different Dell display in the office before. It's good I still have warranty coverage for Dell.