It actually never was approved (certified), only listed in the FIDO metabase as uncertified. Something must have changed on the Microsoft side.
You can change attestation requirements in Entra ID settings, and I believe you can even add specific AAGUID exemptions.
To leave “Enforce attestation” enabled, you should be able to add our AAGUID to the Allow list. This screen shot shows a block list, but if you slide the slider over to Allow it should present a whitelist you can add the VivoKey AAGUID to.
The AAGUID to allow is c84689382e9f4e9382cae59cd24d67d8 or c8468938-2e9f-4e93-82ca-e59cd24d67d8 depending on your formatting needs.