Both @Oscar and @Trish have identified the problem in their answers. Upon further investigation, I believe I found the root of the problem. The Monoprice Select V2 has what I think is an inherent design flaw with how its wires are routed. The wire can sometimes 1) get caught on the frame (when the y-axis is moving towards its maximum position) 2) get caught between the frame and the print bed preventing the y-axis from reaching the minimum position 3) it even hits the y-limit-switch sometimes Here's a backside view of the printer where you can see problem (1) where the wire can get caught by the frame. You can also see the y-limit-switch and I saw first-hand when the wire bundle caught it, forcing another layer shift in my print. [![enter image description here][1]][1] For problem (1) above, I found this solution seems to help [thingiverse link][2] To resolve all of the wiring issues, you have to unwrap the wires and reroute them. People online say this voids the warranty. The wire jamming doesn't always happen. But when you printer moves back and forth along the y-axis hundreds of times for a large print, there's a high probability it snags at some point. This is very frustrating after many hours of printing. And I'm thinking of getting another printer for this reason. I should note that it looks like Monoprice's next version printer, the Monoprice Select Plus, doesn't seem like it would have this problem since the control unit is integrated and the wires don't seem like they would be in the way. [1]: https://i.sstatic.net/nrbpL.jpg [2]: https://www.thingiverse.com/thing:1218943