GrooveAgent4 Looping styles

Hi all, I’m trying to set up a pad to loop a sample while its help and then, when released, play until the end of the sample.

Messing with the Continuous, Until Release and Alternate modes doesn’t seem to make any difference - they all do the same thing. What is the difference between those modes, and is there a way to achieve what I;m trying to do.

Thanks
Adam