AWS managment console does not allow to modify headers or implement CORS

Hello, I've successfully implemented a set of API gateway methods and Lambda integrations. However, when attempting to add a new resource and method today, I encountered an issue. Despite selecting the option to allow CORS, the resources are being created with OPTIONS WITHOUT CORS. Additionally, if I try to enable CORS, a red bar appears at the top stating 'Failed to add CORS.' Manually adding headers also results in a network failure. Currently, I'm unable to find a solution for adding CORS.