Help with GPU Instability Issues After Upgrade

I've been experiencing some major instability issues with my computer setup after recently upgrading my GPU. Here are the specs: AMD Ryzen 7 5700G CPU, Corsair Vengeance LPX DDR4 32GB RAM, AMD Radeon RX 7800XT GPU, MSI B550A-Pro motherboard, and a Coolermaster MWE 850W power supply.

Originally, I had an MSI B450 Gaming Plus Max motherboard paired with an Nvidia RTX 2060 for about three years. A year ago, I switched to the 7800XT, which ran smoothly until about a month ago. Since then, I've been hitting strange errors like Out-Of-Memory messages from Google Chrome and my PC freezing when it's been left on overnight.

The freezing frequency increased, and I noticed that when it froze, the 7800XT monitor displayed the last image before the crash, while the monitor connected to the motherboard showed either a solid green or black screen. After experiencing a session where the PC became really slow and unresponsive, I restarted it only for it to report a USB device overcurrent fault and then completely die. Attempts to power it back on led to nothing working, not even fans or lights.

Initially, I considered a front panel USB short and tested all devices without issues. Then I suspected the power supply but determined it was functioning okay after some tests. I eventually bought an MSI B550A Pro motherboard, thinking it might solve the issue, but I'm still encountering the same problems. Booting without power to the 7800XT has been stable, while powering it often leads to boot failures. I'm leaning towards the power supply being the culprit overall. I'm waiting for support from Microcenter, but I wanted to see if anyone else experienced anything similar and might have suggestions.