X_RECORD_REJECTED
Means
a row reached the record store in a shape it cannot hold
Typical cause
a row adopted into the page's RecordStore that is not an object, or has no record key. It is dropped and reported, never partially merged, because a keyless row would overwrite another record
Fix
x entities show <entity> --json lists the primary key every row must carry. Return whole rows from the handler that built this one