I dug my mini out of storage, downloaded the latest lulzbot cura 2.6.52 and then updated the firmware to the latest and it’s printing in mid air. The nozzle is exactly 10mm above the bed.
I checked out https://ohai.lulzbot.com/project/z-axis-offset-adjustment-LulzBot-Mini/ but when i enter M851 to view the current offset, it’s -1.38 - i’m not sure about setting this to -9. something because that seems like a massive change.
The auto levelling was initially not working correctly - the nozzle would crash into the washers much harder than i remember it used to. There was some build up of plastic and oxidisation on the nozzle so i gentle cleaned that off. That resolved the levelling routine - it very gently touches the washers now like it used to.
Still, when it finishes levelling it goes to 10mm above the build plate, waits to heat then tries to print at that height.