For MetadataCollections and MetadataSources the total amount of records in the list of results does not show more than 1000:

Edit 2 - final solution:

In the filterConfig.js, the query for freeContent , usageRestricted and metadataAvailable should be updated to operator: '=', which will trigger a full-text search.
Since all the fields are part of the fullTextIndex array:

(For the freeContent filter it was working with LIKE search (operator:'=='), because it is also part of the likeIndex array)


Edit:
totalRecords (in ui-finc-config) is just estimated and we have to set exactCount in the RAML schema.json?

The exactCount section is optional and the value of the property is
a simple integer with a default value of 1000 for the
estimated totalRecords hit count calculation.

Also check this bug in other apps, like mod-erm-usage.