Are there any online records that may indicate why a specific DPE may have lost qualifications recently?
Due to privacy concerns, certificate actions are not made publicly available without a formal request, and have to be made via an acceptable means.
The FAA has a document titled Information Provided by PRIA, FOIA, and the Privacy Act which goes into details about how information can be requested and what they will provide:
PRIA is basically a request made by a hiring air carrier, so you wouldn't be able to do that.
FOIA is the Freedom of Information Act, and the above document states:
Through FOIA, ANY enforcement action, whether still open or fully adjudicated and closed, can be reported.
- The Privacy Act allows you to request your own records, or a third party company may request records, so neither of these would apply in your case either.