Done both manifolds on my 2019 did this passenger on 3rd Gen too, same mileage under warranty. Stallantics have a full program and safety stock kits staged, it is that bad. Passenger twice on my 3rd Gen, if stealership is not looking closely they think all bolts are tight, usually rear bolt closest to outlet breaks top head off but stays there hanging by heat shield. I had one cracked manifold we found with dye penetrant, this sounds more like what you might have. At higher rpm initially it doesn’t tick, then ticks then seals up once it expands, But unless you can see carbon deposit…doubt dealership took off heat shield. Hope this helps, for a couple couple hundred bucks you can just replace gaskets and put higher grade bolts proactively, might give you piece of mind, or if you got some money, headers, kinda wish I did that. Hope this helps, until then remote start and turn up music. You won’t hear it.