Hydrogen merit orders don't save properly

[kaskranenburgQ]

Context

The hydrogen merit orders can be dragged in different orders in the front-end.
The merit order of dispatchable hydrogen production can be found here.

In this scenario I installed extra dispatchab;e hydrogen producers. So that the merit order looks like this:

Now, when I want to alter this order, and save it. For instance like so:

Next time I open the scenario, the merit order is back to it's original state:

This also occurs when I try to set the merit order via the engine.

Steps to reproduce

Version (e.g. production/2025-01): Both production and 2025-01.

Notifying @mabijkerk & assigning @noracato for now. Feel free to re-assign