Try disabling crossfire...then run the game in DX12. Does it still crash?
Disabling crossfire will disable whatever magic the driver is doing to pair the cards up for DX12 mGPU...so it will work, but only because it's using one card and that has always worked. I don't like that workaround any better than the 'play with shadows off' option, the whole point of having a 144fps capable monitor is driving it as close to 144fps as you can, and even at 1440p (with max settings), there is no single card that can get the job done.
Its been since earlier this year before I sold of my 290x setup, so it would have been 19.2 or 19.3