The handle is kept upright by four locking splines inside it: if these have broken they can easily be replaced.
You can but the new splines here: https://shop.stewartgolf.co.uk/collections/r-series-spares/products/r-series-handle-spline-set
And here's how to replace them: https://www.youtube.com/watch?v=7InbgsBKHH8