Problems with retraction using Bambu Lab PLA-CF

Is anyone else having end of print retraction problems when using BL PLA-CF?
At the very end of the print using Bambu PLA-CF I get the message that the the filament failed to be retracted from the extruder. This is only happening with the PLA-CF!! Why is this the case ?? It is occurring in different slots in the AMS so I don’t believe it is the feeder, the PTFE runs are fairly short 1 to 1.5m with no severe bends or restrictions. It has happened with both 0.4 and 0.6 nozzles so they are ruled out. The filament has been dried for over 12hours and kept in a <10% humidity container and AMS. Prints done after using the PLA-CF with PETG and PLA basic have no problems!!