J-Link LED D20 always keeps blinking

I am working on RTLS using MDEK1001 kit.
There is a very basic question I want to ask.
On the DWM1001-Dev module there is J-Link LED D20.
This LED always keeps blinking and gets stable only when we connect the module to our PC i.e when J-link Driver is detected.
So, is there no possibility that instead of blinking every time, this LED should be off and get on when connected to PC?
Is there some reason why this LED keeps on blinking?

And second question is, that is there some button/ another way to switch off the device completely without taking out its battery?

Thanks & Regards