Unable to build additional Settlement building
Game won’t let me build settlements even though I have all the necessary cards. Yet all the other players can build multiple settlements.
I don't think you gave enough details for anyone to be able to give you any advice. Have you read the rules and made certain you've met the other conditions, not just having the resources? Could be you've used all your settlements, or you don't have roads, or you're too close to other settlements.