Running Essentials v1.7.1.46-107-g70fdb93
Tested w/ both vanilla and modded pistons/rotors and it seems that essentials is deleting subgrids again.
I only had one player complain twice, but investigated by running a simple cleanup of grids below 5 blocks and it deleted the pistonhead/rotor head grids.
I also checked and noticed some rotors w/o wheels too, however this could have been that they were missing wheels for other reasons.
vanilla cleanup is off as well.