The front and back bunk of the 23B is made up of two mattresses each. A small mattress that is about two foot long sits beside a larger mattress to form the queen size bed. Our problem is on the front bunk. The smaller mattress sinks in to forum a U when you lay on it. The larger part of the queen mattress is fine. The back bunk mattress is also made up of two mattresses that are placed side by side but it does not have this problem. Other than having the front bunk mattress replaced is there a fix? Is anyone else having the same problem? I guess if I have to get new one it will have to come directly from Jayco?
I also have a 23b and though I don't think my smaller mattress pad has ever "sunk" in, it is pretty uncomfortable to be the one sleeping on it...That said, I'd suggest place some additional padding or support under the part that is sinking. Or if you're 5'6" or shorter, like me and my whole family, I just sleep sideways on that front bunk, and let my feet hang off the edge just a little...
We dumped the cheap mattress. (2015 x23b) and bought a queen size air mattress. Takes up a little head room, but extremely comfortable. Helps with insulation and sheet fittings. We bought the mattress at Walmart for about $100. Electric inflate and deflate. Easy and comfortable.