Do they re-inflate when operating? It's not unusual for them to lose pressure over a couple of days, especially with such a heavy load constantly on them. You can use soapy water to find a leak if there is one. I think it's unlikely for the bag to leak on a new coach. If it does have one, it's likely a line or a fitting.
2013 Jayco Eagle 328 RLTS
2012 Ford F250 6.2L 4x4 CCSB W/Air Lift air bags
2002 Coleman Bayside Elite (traded)
Me, Momma and Charles (RIP buddy)
And introducing Sofie!! ;)