Genie lift has sluggish operations from ground controls

Morning gang we have a 1998 Z45/22 serial # Z-45-7018 . All functions work at normal speed from the platform controls , but from the ground controls the primary boom and the telescope boom are incredibly slow while going up or down with the primary boom or in or out with the telescope boom .the secondary boom and all other functions operate at normal speed . We use the ground control station to pretest all the functions before getting on the platform to work . Any ideas on what's causing this sluggish motion because it takes too much time . Thanks !