[keycloak-user] Realm ID value oddity

Hi there, I'm looking at a server with a couple of realms in it (version 1.9.x). When comparing the realm identifiers, I noticed that some realms have UUIDs, while others have 'human readable' values for an ID. As the ID is string-based, it probably does not matter much, but the difference puzzles me. Is this a known ... isssue/characteristic? Regards, Guus