If the fix is simple, I might or might not mention it to the dealer, but do it myself. If it's an appliance or something else major not working, that's different. We bought a brand new class A and it had a couple of small fit/finish issues that were easy to fix with a couple of wood screws and a power drill. Never bothered to mention them because the fixes were easy and it wasn't worth the time and inconvenience involved to let them do the repairs. We live 60 miles away from our nearest dealer.
Mike. Comments are anecdotal or personal opinions, and worth what you paid for them.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 Wrangler JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)