Fibaro 2 Dimmer (212 not 211)

OK, hello everyone… I am a complete newbie in the world of home automation so heads up: I will require some patience and handholding, but I’m 100% willing and wanting to learn!

I am having all kinds of issues with my Fibaro Dimmer 2 module. Followed all instructions on the SmartThings Support Page - Connect/Reset/Remove and first successfully paired it previously with my SmartThings hub; however, the module was not dimming my bulbs. It also did not dim through the Varilight 2-way momentary switch that it is connected to.

So I reset, recalibrated, excluded, and paired it again (though as Fab said, it’s hard to find the right pace of hitting the B-button 3 times to trigger the pairing or exclusion). I launched a Live Chat with an ST Support officer and he seemed to think that maybe it was because it had auto set itself up as a “Multichannel Device”? It has since changed to “Secure Dimmer” upon multiple exclusions/re-connections, but now things are even worse: the app does not show the correct state (i.e. always “ON” even when off; lagging status saying “TURNINGOFF” or “TURNINGON” even when action is completed, and then defaulting back to showing “ON”). Dimming also does not work in the app.

ST Support was stumped and recommended this forum (especially Robin, who I understand is the resident genius in such matters). He started talking about new DTH in the IDE, which are all new acronyms to me! So has anyone else come across these problems, and how can I fix it? I would be most grateful if someone could literally break it down step-by-step so I can follow - a Fibaro 212 for Dummies, if you like, please?