It could be the breaker is doing its job correctly and detecting an Arcing fault. (In new construction it would be common for a nail or screw to have pieced the insulation of the wire. This often won't cause a failure immediately but over time as the house sifts and moves it will eventually cause a fault.)
If the fault is somewhere between the breaker and the first switch there will be no current flow, and therefore no arcing until at least one switch is turned on.
It could also be a faulty breaker. Either way I would recommend contacting an electrician. Finding the fault is probably going to require tracing the wire and breaking the circuit up into smaller pieces until the location is found, then opening walls.
If the home is new construction consult any warranties the builder may have provided. Often this kind of issue is covered under a 1 year guarantee but you have to contact the builder who will use their own crews to repair the issue.