Need help with Creality Ender 3 V2 printer

[heathergraham]

Hello, I have a Creality Ender 3 V2 printer, and recently it has been doing something very odd when finishing a print. When done, it moves the extruder up and starts moving the bed forward (as usual). However, it seems to forget how long the bed is because I hear it crashing into the front endstop, and then it moves back to roughly the centre. I haven't made any changes in Cura or the settings as far as I'm aware, and it always homes perfectly. geometry dash lite
If it moves the bed back, the same thing does not happen. I don't think it's a limit switch problem. The only adjustment I've made is the extrusion steps/mm, which shouldn't affect the Y axis? Is there an adjustment or calibration I should do, or is it an issue with the slicing/G-Code?
Hope that someone can help me!
Thanks in advance!