Okay, I read PPST3 this week (previously I had only read the 2nd edition, not sure why), and I'm implementing the backoff sets outlined for novices near the end of linear progression. With the reduced volume, I'm going to go back to 10lb increase per week on squats, and if that fails I'll go back to 5lbs per week. Given my performance on the press, I may switch to 3x3 for that lift, but I'm not sure yet. I'm going to give 110 one more earnest try.
Squat: 275x5x1, 260x5x2
Press: 110x3x3
Power Clean: 100
Chins: 5/5/5