underextrusion during z-offset cal

I recently switched from an LGX lite to an Orbiter 2 and found that I needed to recalibrate my z offset. I've been trying to do that but the very first tab printed from superslicer always comes out underextruded for about the first half. I'm looking for some ideas as to what might be causing this, I've never seen this sort of behavior before. I'm pretty sure it's not that the bed is too close as I could see the gap between the nozzle and bed.