Every time I use the "Add Edit" tool, Premiere lags

I'm dealing with the most infuriating bug -- it's literally not letting me edit.

I've tried everything with this project, and can't even figure out the source of the issue. Whenever I hit "Add Edit", it freezes up for like five seconds. Sometimes when I import the footage it shows as corrupted and unable to import (I've gotten low-level exceptions, Importer:81 and 39). I'm worried there is a clip/clips that are ruining the whole sequence. Any ideas what the issue could be?

 

 

Specs:

Latest version of Premiere, Version 24.3.0 (Build 59)

Footage is all MPEG-4, AVC

Windows 10 Pro

i7-5820K, 3.30GHZ

32GB RAM

NVIDIA GEFORCE GTX 1650 SUPER