Cutting too deep and broke my bit

I’m just getting started with my PROVer 3018 CNC and Easel Pro.
I did a test run w/ 3/4" birch plywood, and had it pocket cut a shape at a depth of 1/8", but a measurement showed it was a little deeper, perhaps by 1/16", but otherwise it went fine.
I put in a 1/4" piece of walnut, and had it pocket cut a shape at 1/16" deep. It cut 1/8" deep instead, so I told it to stop–and then it did not retract the bit back up–it actually went DEEPER, made a horrible noise, then tried to home itself with the bit still submerged in the material, which of course snapped the bit off, and made a horrible noise when it arrived at the home point.
Also, weirdly, it keeps altering the step distance for manual movement; I have a manual offline controller attached to the CNC, and when I have it set to 1mm, using the controller it will move it 10mm… If I have it set to 0.1 mm it moves it 1mm instead. I have to reset the machine using the manual controller to get it back to normal.
Also gotta love the “Troubleshoot Carve” screen that offers zero help whatsoever!