Is your meter a handheld multimeter or one of the popular built in meters that people are installing as of late?
Link to meterAs wa8yxm suggested it is possible that your meter is slightly off especially if it's one of the $4.99 or sometimes free Harbor Freight meters. I have a Harbor Freight meter that was low by .2v when compared to my Fluke meter.
You might find another camper with a meter and compare a battery reading from both to see if they agree.
Have you tried shutting off all loads and then checking for a draw with your meter? It's entirely possible that something is still on and draining power.