Es300h
 

Just started today. Everytime I step on the brakes while on a stop light, the front and the side cameras turns on. Is this normal? This has never happened before.Thank you!

No... absolutely not. You got a wee bit of a problem there.

I don't believe this is a problem. You might have accidentally enabled a setting where the car will turn on the cameras below certain mph. or it's one of the features of "Intuitive parking assist".

It's a feature that kicks in at ~5mph or lower. Check your manual and you'll find the screen sequence that controls it.

It's a setting. I turned it off on mine. I can imagine a million different ways a similar setting could work better, but not every time I was below 5mph to take over the main infotainment screen with cams.

Mine now only come on when in reverse or if I'm close enough to something in the front to set the front sensors off. I occasionally hit the camera button to the left of the steering wheel if I'm pulling up to a parking spot and want to make sure I'm not going to whack the curb.