Triple displays on Mac Mini lose signal when screen is locked

I have a Mac Mini 2018 (i3) with the Sonoma 14.6.1 installed.

I use external monitors (not Apple). I have three monitors of different models. The problem occurs on all of them. I can't list them all now, but if needed, I can add this information later. At the moment, I am using ViewSonic VX2239wm. I am using HDMI connection.

The other two monitors are connected simultaneously. One via HDMI, and the other via HDMI / thunderbolt adapter.

The problem is as follows: If I need to leave the computer and I lock the active session (Control + Command + Q), then after 5-10 seconds the image on the monitor disappears completely. A message appears about the lack of signal. Sometimes it is necessary to disconnect the monitor for the image to appear again. Since the problem occurs on different monitors of different brands, I assume that the problem lies somewhere in the computer itself.

In a dual-monitor configuration, after unlocking the screen (or waking up from sleep mode), sometimes one of the monitors does not turn on. It also has to be disconnected for the computer to see it.

So I guess the computer at some point stops sending a signal for a period of time, after which the monitor does not see the computer, or something else. Maybe someone has encountered this and was able to solve the problem?

My monitor settings on screenshoot

[Re-Titled by Moderator]