Finally printing my first part, which is basically a 12in tall C shaped profile. It should be perpendicular to the XY plane but seems to be leaning in the y-axis. It's about halfway done as I write this. Now, this is my first CoreXY machine and I've heard uneven belt tension can cause issues with axis shifting, so maybe that's it? Just looking for advice on what to check. There doesn't seem to be any shifting in the x-axis, so I think that rules out skipped steps.