BlueTooth disconnects if Display turned off

My phone works perfectly with the BlueTooth since day 1, untill one day I thought the nav screen is not required since I'm not using it, and turned it off. Then when a call comes in, the phone rings via BT, then disconnects.

First I didn't know what happened and panicked thinking the brand new thing is broken in a week. Then my wife screamed at me pointing out that it must be because I turned off the nav screen.

Sure enough, all phone calls connect and work perfectly if I leave the nav screen on at startup. So I dig up the nav system manual and found this in page 175: "An antenna for the Bluetooth connection is built in to the display..."

I just find it odd that when you turn off the lcd display, you also turn off the bluetooth antenna. These 2 are funtionally quite different. There are times I don't want the glare of the nav screen and want to turn it off, but then it'll also turn off BT! I don't see why they should be under the same switch.

Anyone here have the same experience? Do you think this is a bug or a "feature"?

 

I guess it's better than the bright nav screen, thanks for the suggestion.

But I still worry that the lcd is not going to last that long if it's being used constantly without purpose. Another thread here showed lcd internal cracks appearing all by itself (I think it's called pixel bleeding or something like that) but Toyota refused to replace it as warranty coverage claiming it must be user caused physical damage. The replacement cost was $4000+, ULCH!