>>14078527 (pb), Rusty Shackleford video dig

Video compression is most likely a false lead. Basically whenever you upload something to Youtube, it is force-recompressed through their setup. In general, if you re-compress an already compressed video, the encoder needs more data to mimic the artifacts of compression of the first one, so although the video "looks the same", it is compressed differently, with more data, which mimics your observation.

tl;dr video compressors are source-agnostic and treat input frames as if they haven't been compressed previously, so any artifacts present there will be mimicked - and then compounded with their own artifacts.

Basically this.