1800mm Y-Axis Issues on Expanded X-Carve

I’m a new hobbyist that has switch to cnc for my cage building business due to the accuracy and cleanliness of the machine vs. doing things the old school way by hand. I bought the 1000x1000 xcarve and I expanded my machine to 1800mm on the y-axis. The problems I’m experiencing are that the y axis steppers seem to be constantly getting out of tolerance to each other, so i’m not sure if i’m skipping teeth on the belts or what…Is there an easy way to diagnose this? Also, I know I need to go into the advanced setup mode to switch my y-axis limits, but I couldn’t figure out how to keep it stored? Seems when I try and cut the machine doesn’t go where I think it should go and after setting home (furthest end for max table useage) its seems the machine always tries to go backwards and hits the stops (not good)…Any help would be great.