Recently my Ender 3 has developed a problem of skipping Y steps (layer shift in the Y direction), and it seems to be getting progressively worse. I'd never experienced layer shift before a few weeks ago when I tried some extreme accelerations (up to 3000 mm/s²), which mostly worked fine, but I stopped after getting a couple layer shifts, and now have X acceleration at 2000 mm/s² and Y acceleration back at the default of 500 mm/s².
When the layer shifts happen, I usually hear "grinding" sounds that seem like they're coming from friction of the nozzle moving over the already-deposited material. Bed leveling/height is correct though.
Magnitude of the layer shifts varies between 1 mm and 3 mm. They're all in the positive direction (layers shifts towards the back of the bed).
Speeds are reasonable, 30 mm/s for outer walls, 60 mm/s for inner and infill, 120 mm/s for travel.
Is there a likely mechanical or electrical cause for the onset of skipped steps/layer shift?
Is it possible that the high X acceleration is what's allowing the very high travel speed to be achieved, and that such high travel speed is putting the nozzle on top of cold material that it drags on without giving it a chance to soften it first? Or is the printer underpowered such that there's insufficient current to provide the necessary Y motor torque while the X is under high acceleration? Lowering the X acceleration back to default (500 mm/s²) does seem to make it less likely or less severe, but it's still happening.