That's what we're going for -- a place to start!
And looking at this, everything looks pretty good. One thing that popped up right away and got numerous hits was the MSI B450M PRO-VDH mobo V1 vs. V2 vs. V2 (2nd edition). Apparently, MSI was being a bit naughty in that department and shaved some rather important heatsinks off of the board design. (This, sadly, is quite typical of mass-producers "budget" motherboard designers. Release a model that's actually quite solid [V1]...then start shaving off features for subsequent models without re-branding it [V2 and V2 2nd Ed.] Now, I can't say for certain this is the issue or even a factor, but it's the only thing I could find that would line up with the specific issue you're seeing based on your specs. And it does make sense.)
On the upside, if this
is the issue, it should be fairly easy to detect. Try playing the game at 720p, 30 FPS locked, and monitor your gameplay with a free utility like GPU-Z, which I strongly recommend. (Remember, this is not supposed to be the solution, this is to test if heat / voltage is the problem.) That should take the game down to a performance level that should show performance maxing out at the 40%-60% mark on average. If you receive the hanging / crashing in this case, we can be reasonably sure it's probably
not heat / voltage. Either way, GPU-Z should create a log file that detects any wierdness, when, and where it occurred.
If that initial test goes well for, say, 1 hour of continuous gameplay, raise the FPS cap to 60. Then try 1080p at 30 FPS, followed by 1080p at 60 FPS. Try to see where the instability starts to happen more frequently, and look for any patterns. We'll see what we'll see.