This issue is caused by a break in the spline rings, these are the parts that allow you to adjust the height of the handle. This is usually caused by either forcing the handle open when folded, or by the trolley falling backwards on to the handle when in use.

Solution:
We have updated the design of the spline ring which has increased its strength by over 15 times. It is a simple component to change yourself, please take a look at the following video.



If you have broken these parts accidentally, you can order replacements online.
If you believe the fault is covered by your warranty, please contact our support team with details.