Has anyone run the query on SYSLGRNX, returned rows, then run the CATMAINT PI87933, and found rows remaining? I've only seen it once on a sandbox system but I should probably open a ticket anyway.
I can answer this one myself. UI57390 superseded UI53114 however serviceability APAR PH04042 supersedes the hold action of UI57390.
Code in APARs PI87933 and PI94569 attempted to remove the orphan rows in SYSLGRNX during Db2 11 ENFM process. 00C900BF failures during the ENFM SYSLGRNX orphan row cleanup process prevent the ENFM from successfully completing so this code has been removed in this APAR.