After effects roto brush 3 progressively slows down to a crawl while freezing

When freezing a roto brushed clip, the speed progressively slows down until basically zero.

Is this normal or malfunctioning? Any fixes or ways to alleviate this? It ended up working, but why the absolutely drastic difference in processing speed between the beginning and end of the clip, not to mention the program constantly not responding and nearly crashing towards the end?

Good hardware, recent fresh windows install, freshly installed AE earlier today, 2:45 clip at 1080 30fps of a person in front of a solid background, fixed camera, so clear sharp edges and not much subject movement and no background movement.

The first minute of the clip freezed in about 10 mins with my GPU steadily around 20% usage even with multitasking (I always have a hardware monitor running), then left the pc alone to work and the next minute of the clip took an hour to freeze with GPU usage having dropped to around 5% when I checked it, another hour later at 15 seconds left on the clip it was freezing a single frame in 5-10 seconds with the whole program on the verge of collapsing by cycling between not responding and coming back, with GPU usage alternating between 0 and 1%. Another 45 mins for the last 15 seconds, and it's finally done.

CPU has been floating between 15-20% from the start, regardless of the freezing speed.

RAM was at 60% usage so I'm assuming not a bottleneck.

No other resource intensive programs being used (no other programs actually, except for premiere in the background not doing anything, haven't touched it since I'm using AE to edit a linked comp inside of premiere, task manager showed it was idling and not using anything), multitasking while it was processing seemed to have no negative nor positive influence on the progress.

Also, while the purple bar in the layer window did progress and the preview showed new frames, the pop-up dialog with the progress percentage glitched and got stuck halfway.

GPU acceleration setting turned on.

Running a video game to force more power into the GPU does absolutely nothing, neither good or bad, also after closing it.

ASUS Zephyrus G14 2022

Ryzen 9 6900HS

Radeon RX 6800S

RAM 32 GB