It sounds like you have either a lose wire or a bad panda sensor. I would check this first.
There is updated firmware available. You will need to contact Matterhackers support for this firmware. This removes the smoothieware and runs Marlin. I used this for awhile on my Pulse XE. It seemed to help, but I still had a few bugs I could not solve.
I was tired of trying to fix these issues and I installed a Duet3D mini 5 board. You can find my modification on the forum.
Printer x-axis is still perfectly level. I am in about 15,000 parts since the creation of the modification. I checked the clearances with my calipers and it is still right on. No longer worry about part separation or mid print failures from the gantry being out of sync. Before printing, I set Z=0, probe the bed in 106 spots, load height map and print.
@gonzer I find that printing with the bed hot (75c-85c) ensures that the filament contours into the build surface, specifically the PEI, and I also disable the part cooling fan for the first 3-5 layers
@tinken no disagreement overall, just making sure that issues are addressed in the most logical order. I'm hesitant to recommend things that aren't regularly necessary because I've seen some absurd things over the years - including people loading up with lithium or moly grease to the point where it gums up the lead screws/nuts and requires full replacement of the nuts and printed parts. A dry lube or a penetrating film type lube like you've described TinkSeal being would be much better options than a grease or oil.
From the spec sheets online, the mk8 thread length is shorter but it is still M6 diameter. Therefore, the nozzle will work as long as the top of the threads from the nozzle bottom out on the hotend heartbreak. If the nozzle shoulder bottoms out on the heater block, then a gap will exist inside the heater block causing the filament to leak out and flood the hotend.
@mavin Exhaust fans are not a good idea for the enclosure unless you are only printing PLA. All other materials like the warmer temperatures inside the cabinet. I sealed my two holes off. If you are printing Nylon, the off gassing is hydrogen cyanide, and Nylon requires heat in the chamber.
The tire on this is TPU purchased from tonerplastics and printed on a chiron with a Volcano with a .8 at .88 outside perimeters and 1.4mm insideperimeters at a max speed of 50mm/sec governed at 15mm3/sec max volumetric E. So you can print TPU faster too.
As for switching from PETG to TPU or TPU to PETG mid print - I have not tried that. Some materials stick to each other - some don't It might delaminate where you switch from PETG to TPU