First prints, on the 2nd layer printer goes crazy

New VCore 500 Hybrid (but haven't installed the additional belts yet).
Motion seems fine - can Home, Z Tilt, toolhead moves as I direct it no problems.

Tried printing the first layer test in the commissioning guide; works fine.

Tried printing a Benchy (cause why not?) and first layer seems to be ok, but afterwards the toolhead moves erratically outside the footprint of the first layer, then it jerks to the front left of the bed, and might be dragging the nozzle on the bed as well.

I tried both PrusaSlicer and Orcaslicer, same thing.

Tried a different STL (angryratcam case, the front piece as it seems relatively simple) and same thing - first layer seems ok, after that it goes crazy and heads to the front left of the bed.

New to 3d printing so perhaps I'm missing something obvious - would appreciate any help.

Video: https://vimeo.com/1035812172/51f34a5fc9?share=copy

VimeoJosh Molaver

Bad Benchy

This is "Bad Benchy" by Josh Molaver on Vimeo, the home for high quality videos and the people who love them.