Thanks for the posts folks.
I have passed the information from this thread onto driver engineering for investigation.
I Have The Same Problem Random Blue screens and system freeze
ASUS ROG Radeon RX 5700 XT OC
Asus Crosshair vi Newes Bios
lg 21:9 75hz freesynk screen
Adrenalin 2019 Edition 19.8.2
same here. when I use 60hz monitor mode though, after a while under load playing games, I get black screen and PC shuts down everytime.
I saw this forum a bit ago but thought I'd revisit it to confirm that the problem is still happening. My monitor is 75hz but I'm able to set it to 60. It still sucks I can't use the extra hz. I also get the 30 fps vsync issue and someone told me it had to do with ultrawide. For me that was correct. I set my in-game res to 1920x1080 instead of 2560x1080 and the problem disappeared. Try it for yourself to check too. It really sucks that even in the (at this point) latest driver, 19.9.1, multiple updates later the problem still isn't fixed. The only advice I could give is to make a custom 60hz resolution if you haven't already returned the card. Personally I'm considering just spending the extra $90 on a 2070 and returning this $400 paperweight.