12 week strength squat issues

Hello, I am a 24 year old male 5’10 195lbs.
I have been running 12 week strength to a T and seem to be having issues with my squat.

My squat has been the only lift that I believe to be stalling.
I am on week 8 day 1 and squatted 365x1@9. The last few weeks 365x1 has been an 8 and I have been repping 310x4 for comp squat volume.

This week 365 was a 9 and repping 285x4 for 3 sets feels exhausting.

my nutrition is the same…I am in a surplus of 500 cals a day around 4500 total kcal. 200 to 220g P, 400 to 550g C and 140g of fat. My sleep has remained the same and I have no other life stress that could contribute to this.

Is this a product of fatigue due to the program? My squat 365@rpe 8 hasnt changed for a few weeks but my other lifts have all improved. What could be the cause? My form looks good from a side angle