100% drills but going -7/-8 on sections

I'm registered for the September LSAT (took April) and I'm doing fine on sections (anywhere from -5 to -3 usually) and when I drill specific question types that I struggle with on the sections on their own, I usually get 100% correct! I think it might just be a stamina issue? I do worse typically on full length tests than on individual sections which is why I think that might be the problem. I don't struggle with time (usually end with around 5-6 minutes that I use to review difficult questions).. lmk if anyone has any advice/tips that I could use to nail this down in the next couple weeks!