I installed 3 pendant lights (NEW) with 75W electronic transformer in each, connected to an ark fault breaker AFCI circuit will function properly till I increase the dimmer output to max output for the pendant lights, @ this point about 5-8 seconds the ark fault breaker will trip, this will happen every time whether all other loads on this circuit are on or off. (not overload related) This will not happen if I reduce the dimmer a little from max. Breaker will then not trip with all loads on. So what can be done?

I think trying a new dimmer may work. The existing dimmer must have an arcing problem inside that the Arc Fault breaker is detecting.