1. You always need to evaluate your form.
2. Which part of the lift is failing? Figure this out and then perhaps you need to focus on training this part of the lift so you can break through your sticking point.
3. How many times have you done a pure de-load in those 3 months? It's quite possible your body is fried from the high volume/intensity of that program. It's also possible that you have adapted to that rep scheme.