Smart radiator - Piston working range.

I've been using the smart radiator all winter with no issues, but with spring arriving and warmer weather it can't turn my radiator all the way down.
I've verified that the mechanism works, it just can't push the valve far enough to lower the flow rate enough.

With the original valve it's ok, so I can go manual in summer. But is there any way to adjust the piston working range to use tado all year round?