Lippert RV furniture is notorious for this. The upholstery is bonded leather (ground up bits of leather glued to a fabric backing). It breaks down fairly quickly, especially with exposure to UV. Out of warranty, there is little or no recourse. This problem is not unique to Grand Design, either - it's any RV with Lippert/Thomas Payne furniture. Many folks replace the OEM furniture with something higher quality and more durable. For example, we removed the sleeper sofa (in both our current Solitude and previous Reflection) and have two Ekornes Stressless recliners in its place.
Rob