How did my lifts go down?

Just on the fourth training session of NLP and both my bench and deadlift went down from the previous session.

I have been increasing 10 lbs on squat and deadlifts each session and 5 lbs on the bench and press.

Got all 3 sets on squats with the 10lb jump but with lots of grinding.

Then got to bench and couldn't even get 1 rep with the 5lb jump. So went down to previous session's working weight and barely got 2 reps. Same story with deadlifts. Jumped up 10lbs and only got 1 rep with some serious grinding.

Was really disappointed because my diet has been 100% on point and I was resting really long between sets. I wasn't expecting to stall on the fourth session, much less get weaker, because I started with a pretty non-challenging weight.

Stats from the last session : 230/135/220 @ 139 lbs bodyweight. Eating 4000 calories a day.

Any insights on what went wrong and how I should proceed?

You must have done something wrong. The First Three Questions | Mark Rippetoe

As Coach Rippetoe's article mentions, it's a gradual process and you can't be impatient. It looks like your starting point for the novice linear progression may have been an issue here. If you are on your 4th workout (which means you started last week, if you are working out 3x weekly) and you are taking 10-pound jumps, then you started your novice linear progression at 200 lbs on the squat.

By way of contrast to your program, there is an example of "Well-executed novice linear progression" in Practical Programming for Strength Training, 3d ed. (p. 88-89). The squat starting point is 135. This example was done by a "male, age 35, former Division I college football player." He transitions to 5-pound jumps in the squat at 205. You started at 200, took 10-pound jumps, and your bodyweight is 139. Probably a more gradual approach is called for.