Well mine had a similar moment a few days ago. That was after my first bout of spirited driving, within the speed limit, on a twisty B road. The car handles like a champ, the agile handling assist makes a world of difference. ACC and LKAS were not engaged, I certainly didn't want it steering for me or maintaining my speed. Once I was done, and on a straight bit of road I turned on ACC, normal set speed, the second I pressed the LKAS button that's when the dash lit up.The ACC and LKAS (letters top right) went from green to amber, and it had in the center information area CHECK: ACC alternating with the road departure mitigation and CMBS all in amber. Without the clear windscreen, or the high temp icons. Even the brake icon with the exclamation mark in amber (bottom right corner of display) came on. The drive wasn't very long, and there certainly weren't any screeching tires or heavy braking. I certainly didn't bump or hit anything. Heck didn't even hit a pothole!
Found a safe spot, parked to the side, turned off the car and got out to check for leaves dirt, anything that would tell me why it all went tits up suddenly. Nothing. Got in, turned the car on, no warning, all systems now functioning normally. The car had an electronic fit. Has been behaving normally ever since.
One last bit of information that may or may not be relevant, the radar cover was not properly clipped in when I received the car. There are retaining tabs and open grooves on the top and bottom, but more importantly three tabs that go into slots on the sides. Two on one side, one on the other. Whoever installed in at the factory, managed to get the single tab in on one side and then just jammed the two on the opposite side outside the slots. So there was a gap that was visible on the two tab side. Was easy enough to get all the tabs in their proper place, no fuss or visible scratching or damage to the cover. But that was a few weeks back.
These mobile computers we're passing off as cars these days are frustrating at times, enjoyable at others