[falcolas]

It can be turned off, and there's very little visual indication that this has happened. The feature bugs some drivers, so if you have a second driver, they could have easily done it.

[therealdrag0]

I've toggled it many times to no avail.

[landemva]

Sometimes dealer updates change settings. I saw a Subaru change behavior with lane departure warnings after an oil change.

[gambiting]

I've had this this issue on my Mercedes before, the cause turned out to be the 12V battery that never charged properly, so the system didn't want to activate.