On three of my MacBook Pros (1*Early-2015 Retina, 2*Mid-2011) after plugging in the MagSafe, I get a delay of several seconds until the power cable is recognized. It will first show "Not charging" and switch to "Charging" approximately 10 seconds after, same for the light on the MagSafe.
Tried already PRAM/NVRAM/SMC resets. Someone else having this bug?