After 1 1/2 weeks of daily use, I haven't had 1x problem with signal reception, even with an extension cable. Do you have an AMD GPU? The drivers are sometimes a little bitchy depending on the version. HDR only works in 8-bit mode (GPU setting, not display), which was changed by AMD about 2 months ago.
I only have the problem when it comes out of sleep, then it doesn't recognise any signal from the PC...switching on and off or changing the input helps from time to time, but not always... I have a DP cable 1.4 on it and operate it at 10bit / 175hz / HDR, could that be the problem? If so, is there a more suitable cable? I can hardly find anything for Micro HDMI 2.1...
I have been using the monitor for a few days now and have never had a problem with the signal or waking up from sleep mode. If you want to switch to another input, you have to select it manually in the menu, but that doesn't bother me. You can create corresponding shortcuts on the home screen.