Why is KNLMeansCL slowing me down so much

[Machmir]

I am using Hybrid_2022.03.20.1_SETUP. I have encoded dozens of episodes with multiple filters being used. Suddenly when I try to encode more of the same episodes using the same filters, my fps drops from nearly 4fps to 0.3fps. I eliminate filters one by one to see if it's caused by one in particular and it turns out that when KNLMeansCL is running is when my fps becomes so low. But it didn't cause the problem before so I'm not sure why it's a problem now. Is there a way to update this filter or figure out why it's suddenly causing problems?

I run Windows 10 x64, i5-4430, Radeon HD 6850 1GB, 16GB DDR3