Wow, that's a pretty beefy rig you've built! I am seriously jealous, my computer's getting a bit long in the tooth but is still holding its own. If you can play other games without trouble, the issue probably isn't with your hardware. The most likely culprit is that the currently available production build 3370 of the game, which is very old by this point, isn't compatible with your snazzy new GPU. Don't worry, I'm sure that when the full version of the game rolls out it'll work great!
I'm guessing that your operating system is Windows 10. Are you able to play any other games that are built on Unreal Engine 4? I've seen several weird glitches with UE4 games in Windows 10, ever since Microsoft decided it would be fun to monkey around with the video pipeline without telling anyone. There was even one issue where certain people who tried to play any UE4 game, from PlayerUnknown's Battlegrounds to our humble Descent, would see a weird green stain that covered the entire screen. However, if other games work for you, the issue's probably not with Windows.
As much as I hate to say it, the best solution right now seems to be waiting for the full version of Descent to release. Fortunately, you shouldn't have too much longer to wait! The developers have been working super hard, as evidenced by Wingman's blog here: https://descendentst...ovember-update/
Just so there's no confusion, I'm not a developer. I'm just a fan like you. Hopefully I'll see you in the mines when the full game drops!