Sunspark
I bought the external monitor in January and have always used it via USB-C (which is much more convenient than HDMI since it transmits both the video signal and power) but with the August updates I could no longer use the monitor via USB-C and found that with HDMI it was still perfect.
Now with the KB5020875 update the HDMI port is screwed as well.
Next week I will try to use USBC again, maybe that one is back ok.