It certainly looks like a frame beam, but I have no idea how it could have gotten like that. Possibly something trapped on the top of the slide as it was retracted compressing the siding in? Like a towel or other such that was flexible?
Can anyone tell me what this may or may not be? My unit is a 2013 323QB.
It feels solid when I push on it and doesn't move or flex. This is over the largest slide in the living room/kitchen.
Get this looked at PDQ. I have a Cross Vthat had a very similar BUMP inside and out. I contacted FR about what I discovered and they authorized repair. What was found the header beam across the top of the bumpout cutout was supposed to be welded...it was not, never had been, and was flexing its way into a total failure of the panel from the cutout to the roof. I took it to a local auto body/Marine shop and they discovered the manufacturing oversight...$1500 repair. You also may wish to reinspect the same location in the interior...mine had it also but was difficult to see. Good luck!