interesting lowpass / slow volume ramp which muffles transients *only* when played in a pattern

[coderofsalvation]

First of all, love this tracker, and thanks for all the hard work.

Ok, so here's a simple XM: https://filebin.net/ua5993g4hehmghfz

When you play the sample on the keyboard, it will sound correctly. However, whenever pressing play: the transients (the bright attack at the beginning of the sample) dissappear for some reasons. Is this a matter of adjusting the ramp-up volume of the note-on's?

UPDATE: milkytracker does the same, which might be good news. Is something odd going on with the samplerate etc?