I don’t know if this is a bug or if this behaviour is desired/accepted:
After a merge, I wanted to restore disabled AcoustID links if necessary. …it is necessary (probably contradicting information), but then I saw that AcoustIDs from the merged recording do not appear at all.
A recording, which was 10 seconds shorter, was merged into the full length version of Expresso Love. All acoustIDs of the shorter version were verified¹ and would have been valid for the merged recording too. On acoustid.org, these IDs are still linked to the now vanished recording and redirected to new MBID. But these acoustIDs do not appear in the Fingerprints tab of the new recording². They are gone.
This implies: Possibly false acoustIDs of merged recordings are still redirected to the new MBID, and it is not possible to disable them or even find them on MB.
¹) shorter recording before being merged
(Track "75cd4523-722a-401a-b0fe-e5c8e1621f7b" | AcoustID, Track "af3adf15-0f1c-4fc6-a857-58de90e84608" | AcoustID and Track "c15fc414-4b42-4e47-920f-5c5c3c3b58dd" | AcoustID are no longer accessible from MB.)
²) new MBID (formerly full length version)
(Track "f3e96d7e-99fd-4909-956d-49810e3f1c41" | AcoustID was re-enabled after merge)