So the difference in nozzle height of the left core versus the right core (when down) should be 1.5mm+/- 0.7mm.  It could be that you are right on the edge.  Or it could be failing by a lot.  I would look at the logs.  If you look in the log file you can see exactly what the printer measured for the left and right cores.  This is from an old log file below - you can get these many ways - one way is to insert a USB flash drive and there is an option (I think in maintenance menu) to dump all the l