Why is that every time we open Twinmotion the order of the Materials used in the Project get randomly shuffled. Annoying as hell to find the materials, as there is no search function for Materials, similar to what the Scenegraph has.
You might notice some differences to the way the Materials Manager orders materials when re-opening your file after making changes, especially if you have unused materials in your scene, which could explain the differences you are seeing.
That being said, we are aware that the Materials Manager is in need of improvement and the team is working on an overhaul that should make this far more user friendly and functional. You can see some of the planned improvements on our Roadmap here. At this time, we don't have an estimate available for when we expect this to release.