I made a project with a marker and a model on it. But when I look at it in the view the model jumps a bit and doesn't stay steady on the marker like I would expect it.
That sounds plenty big enough, i believe 3" is the recommended size. I would try another device (phone/tablet), some do track better than others. Also make sure you have plenty of light and are not trying to do this in a featureless white room or similar. I believe View likes to have visible room geometry to help build the tracking model from.
@jmikesell Already thanks for the help.
I have also a marker that is 1.5 scale of the one in the video, so one i put it on the design wall (with lots of different coloured sticky note the jumping is less but still presented).