Nobody said to be OK with it, but you know what your options are. I disagree with RT saying that's "normal" in particular with only owning for 10 months, but it isn't the first time they have had "techs" say some interesting things or just blame the owner. Many of us put Lava-lock high temp gasket on our lids, these should come from the factory with it IMHO and helps with sealing and keeping that from happening to the edges. My buddy has an 1100 and uses it very frequently, keeps it outside uncovered at times as well "does have lid gasket"......not a spec of rust on it. Looks like you have scrubbed the top of smoker with something as well, that's stainless steel vs powder coated lid and perhaps you chipped/worn the edges of the lid?
Also looks like a pretty shoddy powder finish as well, doesn't look very thick or good hammered finish, you can also see the transition of the finish near the top being quite different, do you run pretty high heat frequently? I work in a metal fab shop, I am betting that lid wasn't properly cleaned/prepped before it was coated, and that will work it's way out of the finish in particular with heat applied and UV rays.