Looks like this has been a common issue. Just got 6900XT a month ago. Have been getting intermittent black screen issue but never while gaming. Most often has been while watching YouTube videos. Using latest Adrenaline software and have tried disabling Enhanced Sync but that doesn't seem to help. Also disabled Freesync on Dell S3422DWG in case that was causing it. When it happens a message appears on the black screen saying the monitor has lost the DP signal. Sometimes turning the monitor off and turning it back on and waiting about 30 seconds will restore the signal without having to reboot. When it does restore I get a popup msg saying the Adrenaline software has been reset to default settings. Not sure what else to try but after spending over $1K on a video card I would expect it to perform flawlessly.
5900X, 6900XT, 1000Watt EVGA PS, 32M RAM, Win 10
