I am not from Intel but the problem (garbled monitor flashing between the desktop and something else after wake from sleep) sounds similar to "flickering" which I and others have reported in various drivers after 4080. My monitor is 1920x1200 but single connected to HDMI (I keep an unpowered monitor connected to mini DP). One thread (of many) which has activity near the end is NUC NUC5i5RYH HDMI Sleep Issue
One thing you might want to add is what graphics driver version you are using, and perhaps any other driver versions you have tried. I have not yet tried the latest 4251 driver (the download was messed up initially and since then I've been busy with Windows 10 updates), but my best luck has been with 4222 driver although I have added my own personal workaround of Windows Control Panel-Power Options-Change Plan-Advanced-Sleep-Allow Hybrid Sleep to Off (change from the default On).