MKR Motor Carrier - starts motors right after switch-on


I'm working on a wheeled robot where I'm using an Arduino MKR Wifi + MKR Motor Carrier for controlling 2 DC motors. I'm wondering if it's just me or a general "feature" of the motor shield that when I switch it on all motors are starting to spin/rotate until the boot-process is finished and its successfully connected/talking/getting controlled by the Arduino? (Of course I made sure that until the Wifi is getting control-commands all motor-duties are set to 0) But again ... when the shield is successfully connected/booted/communicating with the Wifi it is all good ... its just really just during the first 1-2 seconds when I switch on the carrier that the motors are starting spinning right away really fast (Its a bit annoying having a speedy-uncontrolled robot during the first 1-2 seconds :D)

Thank you VERY much for help!

Edit: This weird behavior disappears when I'm powering the Wifi via USB or VIN so that it runs before the carrier itself starts operating.