Custom preset materials don't load when a new object is instanced

[tonygr1]

Archipack version: 2.5.1

Blender version: 3.3.1

Os version: Windows 11

Description of the issue:
Custom materials (ex: Red Molding) saved in a Material Set do not load the desired material when you add a new instance of the preset object (for example, a custom Window preset that has been added as a new preset. For example, let's say that Window>Frame out has a custom material (Red Molding) in a Material Set that has been saved. I want to add a new instance of the saved Window preset, but the custom material does not load. As a workaround, you can reload the desired material by selecting (for example) the "Frame out" part on the Material tab (in Archipack) and selecting the same custom material (Red Molding). Then it loads properly, but this is a manual process.