Lexus-SSA

Hello all,
I know this subject had come up before so here is my experience with my series of test after getting my 2nd key.
I left one key in the car (on the front seat, or rear seat or in the trunk), if you try to lock by touching the door handle or using the trunk button, it will not lock and beeps to alert you.
I left one key fob inside and used the 2nd key fob to lock by pressing the lock button !!!! It locked car, although the other key was inside.

Astrid

The beeps usually occur when you leave a key in the car. So leaving a phone that has a digital key set up or a key fob inside of the car will result in a beep when using the door handle to lock the car to prevent a lockout. In the situation you described it locked the 2nd fob inside when you used another fob to lock the car. I assume the car allowed this because it knows you have a key with you since the lock command came from a fob not the door handle. The lock out prevention feature I assume will only be active if you try locking the car with something other than a physical key fob such as the Lexus App or the indentation on the door handle and a key fob is left inside.

Lexus-SSA

Yes, it is deigned and works properly.