Since a recent upgrade, I now always see each print end with a huge (3x3mm) blob driven into the object with the head remaining in the final position. Apart from the slight mess on the final print, this causes the filament-driving teeth to grind the plastic, so that the NEXT print fails to feed any material until I remove the PLA filament, cut off the ground piece, and re-insert it.
I've printed over 100 hours with this printer, it worked fine until the latest upgrade to fw 2.6.2, and works splendidly in every other respect. I'm using a new install of Cura 3.2.1 on macOS with a UM2