That happens with mine occasionally. Just tap the fire button and it seems to get the resistance reading back to where it should be
I guess this is common to the
kayfun and MVP2. Just got my MVP and Kayfun today, and was very excited, but it wouldn't fire on the MVP. The Kayfun fires on everything else, and the MVP fires my T3 just fine. Kayfun+MVP=no fun.
I lifted the pin a tad and sometimes that works. Other times I've been able to fire the button, all of sudden it reads.
I wonder if there's simply some manufacturing film that weakens the connection. Though I cleaned it with alcohol to no avail.