X axis shift when using spool join.  

X axis shift when using spool join.

Hi all, I have been noticing an issue when using the spool join feature. Print is running flawlessly and once it starts the spool join the next tool head is 5-7mm off on the X axis. The print will continue on and print just fine, only 5-7mm to the left of where it should be. 

I have a small print farm and am currently running 5 Prusa XL dual head printers. I love the idea of the spool join feature due to less waste on filament and less spool change overs. 

I have named them all Prusa XL 1 through Prusa XL 5. Prusa XL 3 seems to run the spool join feature with no issues. Prusa XL 5 had a tool crash this morning while changing from T2 to T1. The tool was docked and there was no visible issue that I could see.  When I fixed the error, it changed over to T1, and it was about to start printing 5-7mm to the left again. Prusa XL 1 and 2 completed their spool join with no issues but were both printing 5-7mm to the left as well. Prusa XL 3 completed the spool join with no issue. I figured I wouldn't push my luck and manually changed Prusa XL 4's filament out of fear I would lose the print. 

Prusa XL Dual head, running Sunlu PETG, .4 nozzles, 50-hour print cycle. Prints are nice and clean, just running into a Spool join issue. 

I did calibrations prior to starting this print. Is there something I am missing or is this possibly a firmware issue?