Yeah...it happens. Some RV Manufacturers glue the roofs completly down...rollering glue over the roof before laying the membrane down and rollering it again. My Jayco has this type of roof.
Others I've seen at RV Factory tours are edge glued only (floating roofs)....those are the types you may see as a huge buldge on top of an RV going freeway speeds. One tear and it's "blowing in the wind"!
Shop for the best price on a total membrane replacement...since with the Sunnybrook reputation for quality you are likely to be able to keep the RV a long long time!
More and more buildings are using Membrane Roofing due to the long life and few problems associated with them. Rather that use a RV Dealer or an RV Repair Shop..contact some local home/business roofers who may have experience with installing these specialized roofing products to see it the cost may be less.