I take a bassdrum sample for example and activate warp in tones mode and draw a Transpose Envelope curve inside the clip... LOOP knob is turned off for the sample first.....
I start the transposition envelope at 0 semitones and end up with +38 Semitones across the whole sample...
The curve should look like this....
Now loop that sample in the session view, press play.... and turn the loop button inside the clip on and off and hear what happens to the sound.....
What happens is, that when Loop Mode is turned off, the whole sample is pitched like the very last right point amount... when loop is turned on, it works properly....