Interesting... When I have a CF query that returns a UniqueIdentifier in CF21 from a MS SQL database, it is upper casing the returned key (755220B7-9C18-4D6C-9C91-3A76D26AD2F9) in the results. SQL Server Management Studio does the same thing. Azure Data Studio returns it lower cased (755220b7-9c18-4d6c-9c91-3a76d26ad2f9) instead.

Most likely the difference between database drivers. I know on the MariaDB/MySQL has an option on the connection string where you can set if it's lowercase or not for UUID generated values.