The only things i can think off is that the Monitor cables should not be longer than 3 meters and not active (only use active cables when 5 meters or longer.
Sometimes Bios update for the mainboard (i know it sounds weird) and or Graphics Card does help.
I did hear the “Sleep issue” before, something like the MST Hub needed a new power cycle before being able to communicate again … What firmware version i on the CSV-5300H ?
2 CSV-1564W65 Blinking Monitors and USB Device Not Recognized
4 CAC-1010 and 2 Dell 3007WFP-HC monitors. 1 works, 1 doesn't
6 USB3.2 Gen1 Type-C to Dual Link DVI-D HDCP OFF version Active Adapter M/F for Apple Cinema
7 3D club
8 CAC-1531 USB Gen1 Type-C extension cable won't connect mouse and keyboard