Windows 10: Old external monitor blinking WIndows 11 problem suspected

My external monitor connected to my Surface Book 2 is blinking on and off. It is connected by a USB-C to VGA adapter older monitor which has been working fine until now. I switched to Windows 11 last year and fear that an update has caused this to happen. I have updated all my drivers so they are all current. It is not hardware as external monitor works well with another laptop still on Windows 10. I doubt that the fault is my USB_C port.

:)

 

external monitor blinking

huh? i restarted in safe mode to see if external monitor still blinks but external monitor doesnt work in safe mode.

 

external monitor blinking

in addition to the sleepy pc blues in my other query, i forgot to mention the random blinking of my external monitor. it is an envision by ADC 1080 p monitor that worked no problem with win 8.1. after updating to win 10 my monitor blinks about every minute
or so. just goes black for 1 second then comes back on, so far,. i wonder if that and the sleep issue are somehow related?

i have tried the troubleshooters in win 10 with no success. i have tried a couple different refresh rates in display settings as well , no luck.

 

External Monitor blinks and flickers

I have a YOGA 900 connecting to external monitor through c port to HDMI adapter--external monitor screen blinks on and off and flickers. I have tried disconnecting all cables holding power button down for one minute with no change. Is this a setting, a
windows 10 issue, an adapter issue, or what?