Error when creating record type

My database has a primary key and it is unique.

CDT has been created from the database, and with same primary key as database.

But when I create a record type from this entity, I get UI error when saving the record type. What can cause this?

The System Has Encountered an Error

HTTP Code: 500 APNX-1-4198-000 Error Evaluating UI Expression Expression evaluation error [evaluation ID = 8OWKHVBV] : [valid:false,syntaxError:false,value:Expression evaluation error: An error occurred while executing a save: Expression evaluation error at function a!rtd_sanitizeRecordType [line 549]: Keys must be unique (case insensitive match) [createdby]]

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