Lost plunger control on OTG Pinball FX

Not sure as to what has happened to my plunger when playing Pinball FX via OTG, it was working just fine. The plunger works fine for the tables on the ALP HD, and it registers in Steam when testing the controller as the down Z axis. I've remapped several times using Steam and replaced the OTG cable. Anyone have a fix or similar situation?