Missing squat reps early in LP

Hi I am a 16 year old weighing 170 lb at 5’11” and I started the SSLP in late July. My starting weights were 95 squat, 85 bench, 55 press and 135 deadlift. Right now I have 185 squat, 110 bench, 80 press(will need to start microloading soon), 225 deadlift, and 85 clean(trying to get form right). Today I attempted to squat 190 for 5 reps and I was able to get 5 reps on the first set, bud I failed the last rep on the second set. I then got 5 reps on the last set. I remember Austin saying that the average squat after LP is 285 and I don’t know why I am stalling so quickly. Do you guys have any advice?

Thanks for the advice. So should I focus on sitting back in the squat more? And also how can I work on making my back tighter, is it just squeezing the shoulder blades?

How much did you weigh when you started, and what’s your current waist measurement?

I started at 150 lbs so I have gained 20 lbs. My waist is around 30-31 inches. All other lifts are progressing well.

Invest into some lifting shoes you won’t regret it.

You need to work on breathing and bracing properly. This is not a good position to be in at the bottom (see the image attachment). Learn about “proud chest” Lea Lutz has video on it to fix your upper back: https://www.youtube.com/watch?v=nhzRIBvwhUo and watch this JTS video to figure out how to brace your core and lower back: https://www.youtube.com/watch?v=ZFiosv9_vis

When I was a novice I remember i could get away with being loose and muscling it up and getting out of position with my back hips and knees. But as the weigh gets heavier you will feel “stapled” and feel like power is leaking immensely, it’s night and day.