the reason why it is peeling is because paint does not adhere well, for the long term, to the TPO rubber roof surface. mine is doing the same in several places, mainly the front and rear ends.
I used the black 'silicone rubber' type spray[as seen on tv!] to 'repaint' these areas. I feel this will adhere and stay much longer, and better.
If you look at how your roof substrate is constructed, it is pulled over the top edges of the walls of the coach, several inches down the sides. If they did not paint this edge of the 'roof', the unit would then have a white stripe around the top edges, which we would probably also complain about... : )
While Thor provides you additional PAINT(probably in one of your cabinets) for these type of situations, I think the silicone rubber is a good replacement option, and they have different colors to match different situations as well...
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada.... formerly GA, then AL, now back to north Georgia! : )