After setting which armours can be equipped in a class's characteristics, closing the data manager, editing some other things, and opening the data manager again, it seems most armours' equip settings are reset to weapon type #1 (in my case that;s "Sword").

This is happening on the latest Linux version from Steam; v2.0.11

In the screenshot below you can see what that looks like, every "Sword" in that screenshot should've been a different armour, instead.

This happens in every project, including the example project.