I'm having a very similiar issue. My PC freezes in the same way. It only happens at BeamNG Drive. Power Supply is a 700W Bequiet Gold. Ran DDU Windows 10 is freshly installed 1 month ago. With higher and lower power limits the same issue. And Radeon RX 580 runs fine in the same System so it's definetly a GPU/Power Supply issue. Any Battlefield is crashing me to Desktop after a random amount of time as well.
I can see in all threads one solution "do ddu an it will fix everything", it's repeated like mantra, and from what I can see, in 99% of cases it did nothing.
it's not a bug, it's feature
often DDU fixes a corrupt driver install - its always worth a try
but if there is a HW defect or instable OC than DDU wont fix it...
When checking the recommended PSU for your graphics card, it seems to be 850w and not 750w, as you currently use. The AMD graphics card are known for having huge spikes of voltage occurring from time to time during load and perhaps even during normal usage and it may therefore be stable during times, and then an influx of increase voltage occurs suddenly, and if your PSU is not strong enough, the system may crash or reboot.
As for the common black screen issue, this is mainly fixed by reinstalling your graphics drivers with a factory reset and deletion of saved precepts. You do a factory reset in the beginning of the driver installation. This fix has always worked for my own black screen issues, and I use a Vega 56.
As for my self, I specifically bought a 1000w PSU for my Sapphire Vega 56 graphics card in order to comply with the 700w PSU recommendation, and in order to future proof my self.
If you try a stronger PSU, at least a 850w to 1000w, your sudden black screen issues of your system may be avoided.