Shield bot and Grove Servo does not work together!

Hello! I have a servo motor (https://wiki.seeedstudio.com/Grove-Servo/) and a Shield bot v1.2 (https://wiki.seeedstudio.com/Shield_Bot_V1.2/).
Normally car works okay but when I attach a servo it stops working (servo does work). It stops working even when there is no servo physically connected. It just does not work when I do myservo.attach().
By “not working” I mean the motors that drive the car stops working, but other modules attached (including the servo) does work.
Using different ports haven’t solved the issue.