By ‘did that’ do you mean you turned off ‘Auto-home on startup’ because your machine does not have limit switches?
If that’s the case, you’ll need to manually home your machine by moving it by hand to the bottom left corner before turning it on in order for the ‘Absolute Coords’ Start From mode to work properly.
Here are some resources on the way the different Start From modes work:
If your laser does have limit switches, and you’re unable to get them working properly despite checking on the wiring, you will need to contact Atomstack, as that is a hardware issue.