Roland VH-11 'slurp' triggering issue.

[Marimbo]

After replacing my TD-12 module with the Edrumin I've started to experience a triggering problem that wasn't there before:
When I open the hihat from closed, to get the 'slurp' sound, about 80 percent of the time, the hit will be 'dead' meaning no sound. There also is no signal. It seems to be less prevalent when I hit really hard.
In closed position there is no issue, and hitting it left open doesn't reveal any errors either. Only when I open it momentarily when playing closed.

This was never an issue with the Roland module, and that is the only hardware change. Anyone else had this issue and managed to mitigate it? Or have any ifea what might cause it (trigger settings?)

[Rob]

What firmware version are you using?