Iconia B3 never shows dialog to allow access when connected with USB

sweettea

Hi everybody,

I recently purchased Iconia B3 tablet.  I updated it to Android 6.0. I set up security code to unlock the device. However, when I connect the tablet to PC I can access the internal storage as well as the memory card of the device even when the device is locked.  When it is unlocked and I connect the device to the PC it never asks me to allow access to the device (or new device); the flash storage is always available from the PC as soon as I connect it to the PC.  Is this normal behaviour with Acer tablets?

I would like to flash storage NOT be available to PC when the device is locked.  I would like the device to prompt me with a dialog to allow access to flash storage when it is unlocked.  How can I change the behaviour?