Sampling Help with Groove Agent - sample cutoffs and audio auditioning

I am just starting using samples in Cubase and having a couple of issues I was hoping someone might help with

  1. I import my sample and open Hitpoints to chat edit but when I select playback slice there is no sound (I am not not on mute) and otherwise the sample plays as normal when I press play on the timeline - this means i cant audition each slice

  2. I drag my sliced sample in C1 of Groove Agent and all works but I like to program using GM mapping - I change all slices to One shot in Groove Agent otherwise it only plays the first “hit” sound, but sometimes I will want my new sliced sample to cut off the previious sample mid-way - how would I do this so it would work for all samples?

Also to mention I have tried turning poly to 1 and set all pads with samples to Excl 1