I don’t think I’ve ever had a mobile phone (and I’ve had them since my first brick NEC 9B) 
or a PDA (Palm Pilot 100) that when it is turned off and plugged into the power turns itself on?
Normally if it’s off then it shows a battery charging indicator only.
Normally if I’m plugging in the Mudi it would be to charge it up only. As I say if youre not aware of this you may find the Mudi flat when you really want to use it.