Creality CR-10S: Bed is miscalibrated, printing off edge

I'm using Cura to slice my prints.

For a while when I started a print, the bed would zero out (move all the way to the back and hit the switch) before the print started, so the printer knew the bed location.

Sometime recently, (maybe with an update of Cura?) the bed no longer zeros out, and it just starts printing wherever the bed is sitting already, and so becomes miscalibrated, with the printer trying to print off the back edge.

I've googled this problem, but the only solution people mention is to uncheck "origin at center," but that's already unchecked.

What happened? How do I instruct the printer to zero out/calibrate the bed location? None of my prints are being printed at the center anymore.

Sounds like one of the end stop switches.
With the Nozzle in the center of bed send

M119 - Endstop States

Then check each end stop pressing the switch and sending the End-stop States code.

I found the error. The default settings in Cura for the CR-10S list the Y depth of the bed as 300mm which is incorrect for my model, My CR-10S has a bed of only 230mm.