I have a pass
thru that has been acting up as well. The first time it acted up I ended up blowing into it and it worked after that. I'm assuming it was a stuck switch or something. This symptom was similar to yours.
tonight it would heat up the atomizer, and I've found these things are real finicky about making a connection to the atomizer sometimes, so I just kept unscrewing and screwing the atomizer on it and it finally started working.
Maybe one of these will fix it.