This is a game that the CRAs and CAs, more specifically JDBs, like to play. Could be a really old debt beyond the CRTP. Could be a debt they cannot validate and have no proof of it as even belonging to you. Might not even be yours.
Anytime you get a call, letter or entry on your CRs for something from a CA that you don't recognize, or is too old to report, DV it.
Just keep monitoring with TC. If it shows up again under a new CA, DV it. If the same CA doesn't FOAD, then they are in violation.