I wasn't sure what you were talking about so I want out and took alook at mine. I have the metal wrap around awnings, the metal strips that hold awning to wall sides has a ribbon 1"type caulk that comes in rolls under these strips. I found that some of the stainless steel screws need to be tightened up which will squeeze the caulk strip tighter to the wall. The strips for window awning all the screws can be tightened if screws for slide awning need tightening thats a tougher job.
The sealant your talking about is it where the topper cover meets the metal wrap?? Mine just slide thru the metal warp strip no caulk. IF you find that water is getting thru this strip you could use any sealant to stop this.
The sealants will mildew and I have used some deluted bleach to remove or a good black streak remover.
If your awning strip is pulled away from wall I would just tighten the screws on same caulk if its worst than that see a Dealer your still under warranty.
If you don't have a metal wrap
than I would just tighten the screws to squeeze the caulk that is under the metal strip, BIG JOB if you want to replace 1" ribbon strip.