First, these switches are incredible and the community here is awesome. So thank you for being awesome.
I have 2 Blue 2-1 switches and a few more on the way. Almost every switch in my house is a 3 way, and none have neutrals. They are wired up in the way pictured below.
While I waited on my Add-on switches I just bypassed one of the 3 way switches by caping the traveler and connecting the line and load together. The new switch functioned perfectly, and worked as a dimmer. Today the new Add-on switches came in, so I wired them up and was able to get the working with the exception of dimming. The blue LED on the Blue Series dimmed like it was supposed to, but the lights didn’t dim at all. Here is the wiring. Any thoughts as to why everything except dimming works?