Hello, i'm new to cnc and software, still playing around.

It was doing a 3d finish operation, near the end of the gcode i wanted to see how many passes/width still left, so i lead to mach3 toolpath preview window and left click and drag, left click, right click, double click, middle click, so basically i tried everything there with the mouse. Then when i got the desired preview i notice the machine not on right Y, i stop machine right away and check stuff. I send a Go To Zero to check home and home was altered in Y, it was some cm lower than expected.
What caused such problem?

Mach3 with LTP. First time this happen just because i mess arround with preview window.

Here the disaster:
Attachment 436912