Clean ALL the Crap they have applied (Inside & Out) of the (Gap) with Acetone! Now take a Pencil and wrap a small (Patch) of Eternabond around it! Like 2x3.Now place the pencil down in the Gutter with (Equal length) of Eternabond on each side of the Gap INSIDE! Now Roll the pencil out and trim the ends of the Eternabond! This will produce a (Strong/Smooth) bridge over the (Gutter Gap)! Buy a Small roll of (Eternabond) you will Need it anyway!
PS do the (Other Side) while your at it,cuts down on (Black Streak Lines)!