I have the same symptom, brake warning and low wiper fluid warning stays on for 1-2 minutes after starting the car and immediately starting to drive, and then both disappear at the same time. If also seems that if I use summon 1st to get the car out of the garage, then the duration of the warning lights is shorter. I took delivery on Thur 7/5. I didn't notice it on my 1st day, possibly because every time I start the car I end up sitting around for a bit and play with some settings. They told me there was a FW push to my car the morning before delivery. I'm on 2018.24.1.