No glue needed for ANY ABS or PLA parts on PEI.
DO NOT use the XYZ bed calibration, it sucks.
Calibrate by hand on a freshly heated bed.
Get a print running(any print doesnt matter) you just need the bed and print head hot.
Right as it starts moving the print head to home, shut off the printer.
Have a piece of printer paper handy to use as a gauge.
Wipe the bottom of the print head with a cloth and make sure the filament is retracted a little
so it does not seep. CAREFUL, the print head is near 400degrees F!!!
Move the print head over the bed, start in the back left, right over the adjustment wheel.
Slide the notebook paper between the nozzle and the bed and raise/lower the adjustment lever
just so the notebook paper barely drags, it shouldn’t be loose and it shouldn’t get stuck.
Repeat this for the right hand adjustment wheel location and the front center adjustment wheel.
Once the front is done, double check the left and right spots by moving the nozzle back right above the adjustment locations.
This is the best way to get perfect bed leveling.
For PLA fold the notebook paper over once for double thickness as you need more of a gap.