Tone when opening driver's door

Hello all,
New member here. I've joined b/c I have a new condition in my 2016 Tundra that started about a week ago, and it mystifies me.
When I park, turn off the ignition, remove the key, set the brake etc, the truck now outputs a steady "beeeep" tone when the driver's door is opened. It stops when the door is closed. This is consistent.
Have I inadvertently bumped a switch somewhere?
TIA,
Snowslide

 

BTW, I don't have a sunroof and after it has been parked for a bit I can open teh door with no tone.
-Snowslide

 

Is the headlight switch off?

 

A constant beep? That's a new one for me.

 

That's a good point. I've had it switched to daylight running / auto for years. If that's it you can just color me stupid.

 

Welcome from OKC! Possibly an ignition switch wear issue???

 

Did you ever get this resolved? I’ve got the same issue. Thanks.

 

Yeah, mine started doing this too this past week...it's confusing because everything is shut, off and removed (key)...