Have you tried this?:
Center console screen, Settings button, located bottom right side of the Home button. System prompt volume, I know it adjusts and holds the volume for the reverse and cross path sensors. I would think it would also control the front sensors as well. Quite a range there, ours is set mid volume, which is kinda too loud. See what yours is set at, hopefully resetting to low may be a lot more tolerable and solve the default dilemma when restarting the engine. Let us know.
2015 Lincoln MKC AWD 2.3 Reserve 19" 5-spoke Climate Pkg. Ingot Silver/Ebony
2012 Jeep Grand Cherokee Limited 4X4 3.6 20" Bright Silver/Black