Settling over several days is common. But if 12v. is available (main switches not shut off for storage) and the leveling control is set, the auxilliary compressor in front of the entry step underneath (on most rigs I've seen) should help keep enough air supplied to overcome settling tendencies. Is that compressor functioning? As per recent threads here, they are subject to failure.
The loss of air, if unusually significant, could be from various sources, not just the bags. I'd crawl under (with proper blocking diligence and safety care) and check the compressor contacts, fuse, motor, and wiring, then be patient and consider a trip that works a stop in at one of Jerry's good suggestions for a checkup. But be aware that if the air loss is considered normal and relatively minor, as ours is, the facility may balk at checking because microleaks are very time-consuming to track down, and may still be undiscoverable; from a practical point of view, they may not think you should endure the labor cost involved.
If you are anxious to get it looked at, you may also consider Mobile RV Technical Services. If Dana is still there, he did some work for me on our old coach 7 years ago, and was pretty savvy: www.MobileRVrepair.com . 503-209-2602. Due to them coming to you, there is some added cost to it. But I don't blame you, Olinger's would not be my first choice for service, even though you are nearly next door to them.
Joel