If nothing has changed in your application and you are having issues with search, that may be related to a major incident that has affected over the past few weeks specifically Lucene searches on free accounts, you should contact support to see if its related to that.
If you have upgraded your application to use the API from v1 to v2, or switched on OIDC compliance, or created a new instance of your application that uses new Auth0 client (which would have create this with OIDC enabled) this will affect how metadata is returned.