MacBook shows Power Source as Power Adapter even when unplugged

I had this issue once, SMC reset didn't help neither nor turning the option off and on again...

What I did was:

  • I turned off my MBP without beeing connected to a power source
  • I connected it and waited until the charging logo appear
  • I turned it on still connected

After that, it came back to normal

(I noticed this bug when I was looking at the istat menu battery log while pluggin/unpluggin the power source)