2024 GMC Terrain SLE Transmission
So I bought a 2024 GMC Terrain SLE with 8000 miles on and it was fine when I first got it but then I was sitting on lunch one day and it said it had an update that needed to be installed, I thought maybe it was something for the infotainment system but when it was done it said an update was applied to the TCM and I didn't really think anything about it but ever since then it seems the transmission has been acting weird, like highway driving it's great but at low rpm or when coming to a stop or if you take off slow it seems to not shift smoothly or has a little kick to it and I took it back to the dealership and they said it was low on transmission fluid but it seems to still be happening, it doesn't happen EVERY time I am not sure if it's maybe the update or since it's a 9 speed transmissions it just normal because of how fast it has to shift and down shift or if something is actually wrong.
The dealership says it's fine but should I get it checked out by another place to see if they think something is wrong, would the dealership even listen to me if it was an issue found from a third party company, I still have the factory warranty but can that only be used at a dealership to get it fix or replaced if it needs it? I don't really trust the dealership's :/