Weird freezing issue with Radeon VII

I've been trying to figure out this issue for a couple days now with no success. Hoping someone might have some insight.

Switched out a Sapphire Pulse RX 580 for a Sapphire Radeon VII and have been getting system freezes randomly without any patterns at all. Everything boots up fine, although does do a weird wavy text thing right before getting to Apple logo which I never saw with the 580. For the first week everything was fine. In the past 3 days I've been getting these freezes where the mouse stops responding, none of my iStat data updates and I then have to hold the power button to force a restart. It can go usually a few hours before it freezes. But no patterns at all. The mouse has gotten very laggy right before freezing a few times. Others I'll come back to an unresponsive computer. Been hard restarting about 5 times a day.

I initially thought it was the vbios on the VII card so I checked and it was up to date. Then I thought it might be a power issue (Corsair RM 650 Gold) so I bought a Kill-a-watt to test power. I threw a bunch of stuff at it simultaneously and the most I saw it hit was around 200watts. I did a Premiere Pro 4K timeline export, Handbrake conversion, large file transfers to all my HDD's, etc.

Tried HDMI cable instead of DisplayPort, that didn't work. Went into BIOS settings and re-checked everything, still getting the freezes. Reseated all the power supply cables. Checked for any memory leaks. I can't figure this out.

If anyone has experienced this same issue and has a solution please help! Or any ideas welcomed.

Hardware:

i7 8700k (no overclock)

Dark Rock 4 cooler

Sapphire Radeon VII

Asus Prime z390-a mobo

Crucial 32GB 2400 RAM

Mojave 10.14.6 is on Samsung 970 EVO 1TB

Crucial P1 1TB (project files for Premiere)

6 TB HGST (long term storage)

6 TB Seagate (long term storage)

4 TB HGST (long term storage)

SMBIOS iMac Pro 1, 1

iGPU disabled

Using the normal kexts that I did with RX 580 (WhateverGreen, Lilu, VirtualSMC, etc.)