Hey Bryce,
I’ve been noticing I’ve been having the same issue. Everything is the same on my end in terms of hardware (i.e 1TB T5, Prores HD). Typically a clip will drop a fraction of a frame causing the video image to not be in sync with the audio recorded to the clip. I figured out a work around in Premiere by interpreting the footage and assuming the new average frame rate. However, this only works for me because I record my audio externally. Otherwise the footage wouldn’t match the audio recorded to the clip.
Have you determined the culprit in the matter? Seems like a faulty cable would likely be the cause but you’ve mentioned you already tested that…