Flickering issue with LG UltraGear 27GN950-B monitor

I'm having an issue with my Razer Studio 2020 Edition, serial number: BY2023M02301728.

I recently bought an LG UltraGear 27GN950-B monitor and after plugging it into my computer I noticed that there's a flickering issue when the monitor is plugged in. It will also randomly cut off out of the blue and then cut back on. The colors don't look as rich as I'd expect either... I feel like there's some setting that's off.

I use the monitor with my Mac and it works fine all day. No flickering or cutting off issues and I'm using the same HDMI cable, that's why I'm thinking its an issue with my computer and not the monitor. My friend told me to use an HDMI -> DisplayPort cable to take advantage of the monitor's NVIDIA G-Sync feature, and when I plug it in, the computer doesn't detect the monitor.

Is my model not compatible with DisplayPort? Its a gaming PC + a gaming monitor, are these sorts of compatibility issues common? I'm a bit ignorant to how to think about this as I've been a Mac user for the past 20 years, so I'm used to things mostly just working straight out the box. I just recently made the switch back to PC - just wanted to give some context behind why I might be missing something that is glaringly obvious.

The TL;DR:
1. What might be causing the flickering/turning off issue?
2. How can I take full advantage of the full capabilities of the monitor using a DisplayPort cable?

Thanks!