Yeah OBS is saying it's a terrible network connection causing it, and like, my upload isn't amazing, but it's holding around 7 Mbps which had no problem doing 720p 60FPS previously.

This might seem like a silly question but are you using simple or advanced in the OBS stream config? I had so many odd encoding issues until I forced it to the "simple" profile. Tried all sorts of bitrates and settings, nothing worked until I switched it to "simple"