Should Day mode turn off automatically?

Firstly, No, the dimmer wheel is not clicked into no-Dim mode


OK so my Mother In law recently purchased a 2020 Prius.
She has recently had an issue with Day/Night mode.
She can turn it on manually, but swears it used to turn on by itself.
She has been to the dealership 4 times and they are basically useless.

Should this work automatically when the headlights turn on in full?
If it Should, how the heck can I fix it?


Thanks for reading!