I’d like to reproduce your symptom(s) . . I’m suspecting a bug is involved.
How ( in detail ) do you perform a Z calibration ?
Do you simply press the CALIBRATE Z button on the Device page ?
Do you have ENCODERS or END STOPS enabled ?
Thanks.
UPDATE
I can reproduce a Factory Reset after a Z axis movement timeout is reported from firmware.
I’ll open an Issue on GitHub FBOS.
@danisam, to get your bot running, we ( the FB Community ) will have to help you find out why your Z-axis movements are timing out. This will avoid the bug which causes Factory Reset.