Input field value is not reactive

Hello,

I have woodplate positions in a side bar and a form with width and height. If I click on a position, then the input fields will be filled out with width and height in the form template (simplified version):

<template name="size">
    <form>
    <input type="text" class="form-control" id="width" placeholder="in mm" value="{{width}}">
    </form>
</template>

And now my problem: If I change the text of the input value by hand without submit my form and the go to another position, the text inside the input field doesn’t change. Has anyone an idea.