Performance drop for a specific scenario in 23.3, which worked fine in 23.2

I have a specific bug I just started encountering. It appear Premiere just upgraded to 23.3 sincxe yesterday and I immediately began encountering a performance issue I wasn't having before. 

In my project, I have a 4K30 sequence using 4K60 ProRes 422 footage (the source footage has 5.1 PCM audio). I have been working on some VFX, which I render to ProRes 4K30 with 4444 so I can make use of the alpha channel. I place these on a layer above the main edit, and on the top layer I have an adjustment layer with a LUT applied in Lumetri. 

The problem occurs when I play back the parts of the sequence with these VFX clips overlayed over the original video. In 23.2, these play back just fine at full resolution, 4K30, and in 23.3, they immediately cause my computer to drop to 1fps or lower, with 100% CPU utilization. Lowering playback resolution to 1/4 does seem to sometimes fix this, but is an unacceptible quality loss, and not a consistent fix either. Turning off the adjustment layer doesn't solve it either.

CPU: AMD Ryzen 7 2700x

GPU: NVIDIA RTX 3080Ti

64 GB RAM, and all footage is stored on two two SATA SSDs striped together for faster read speeds. 

I downgraded back to 23.2 and it's working just fine again, so it's definitely something that changed from 23.2 to 23.3.