We have the same model 2701DS. Going to let the DW answer this one:
Hi, we love the bed and find it very comfortable.
Is your bed made up with sheets and a mattress pad?
I found with a fitted mattress pad, it was was very difficult to get the mattress to lay flat. The mattress pad kept pulling on it, keeping it from extending all the way without a huge struggle. I ended up cutting away the two corners at the bottom of the pad, but left the top corner intact so they stayed hooked under the mattress. The bottom of the pad is now loose, so the mattress can be adjusted easily when extended. I just reach under the sheets and mattress, grab the corner at the split, adjust the mattress on one side, then do the same on the other.
Along the same lines, be sure your sheets are not too snug, or you would probably have the same problem. "Deep pocket" sheets work fine with ours.
Hope this suggestion helps.
2004 Winnebago Minnie 22e(went to a nice family Oct 3, 2015)
2016 Forester 2701DS (Aug 31, 2015)
2015 Camping 3 trips 6 nights
2016 Camping 9 trips 28 nights