Sorry this took a bit to get back to, but. I'm innocient! This was Bunkr renaming the files and inserting stuff (no clue why or anything, still relatively new to bunkr).
The split archives will remain, because many of her videos are over 2GB, and I'm not re-encoding a bunch of videos.
Eventually, I will reupload the archives, probably as 7z archives instead of .zip, and see if that goes more smoothly. But until then, a temporary fix.
I noticed the .001 etc. files had an extra .zip..... inserted, so my fix was to rename the downloaded files from "-2023-08-29-JD-SEX-.zip-BBubTgAX.zip.001", to "-2023-08-29-JD-SEX-.zip.001", removing the ".zip-BBubTgAX".
I did the same procedure to the .002 file, and the video extracted correctly.