LZW31-SN 4-way Aux switches acting strange

My aux switches act very strangely. When I pressure up button, I hear a relay trigger on the dimmer, but no lights. I have to hold down the aux switch and/or click the down button to eventually get it going. No dimming via aux either. My wiring has full neutrals on every switch and is functionally identical to page 14 in the wiring guide (attached).

Also, the dimmer switch buzzes quite a bit when I command dimming. Not sure if this is normal.

Any ideas on what could be wrong with my setup?

Did you change the setting from 3-way toggle to 3-way momentary?

Bingo! Set to momentary and voila!
Many Thanks!