PTC does not support a "list of materials" Users can create a Repeat Region that displays information and it is possible there is something about the Repeat Region that is not working as you think it should. It's also possible that it isn't a Repeat Region and is just a dumb table, though that is less likely.
Understanding what can go wrong in a Repeat Region is not easy to convey. You need to post at least a picture of the model tree and switch symbols to show a picture of the Repeat Region parameters. You may also have to look at the Filters assigned to the particular Repeat Region.
