When it comes to Midi transmission, native mode for the Jamstik is 6 channels. Sometimes certain patches or apps only respond to Ch. 1 input, and you may have inadvertently switched to the other midi-channel mode.
Let's try switching to single channel mode.
To do this- press and hold "Enter" on the Jamstik and press the "Right" button on the D-Pad to switch Midi out from 6 channel to single channel mode.
If you want to go back to 6 channel repeat the same steps.
Here is a video clip with similar instructions.
If this does not solve your issues, you can perform a, "hard reset" of the Jamstik detailed here - hard reset instructions.
*note - it is also important to keep your fingers clear of the fretboard when powering up your jamstik, as they can interfere with the initial calibration of the frets.