NVD REST API continues to be unreliable. A migration to the FKIE git based data feed for CVE NVD data might be worth the stable exception.
A good starting point: cve-update-db-native: add the fkie source https://git.openembedded.org/openembedded-core/commit/?id=f6253ac8189db09fbe87141aca1733cb37a4d78f That was later patched with: https://git.openembedded.org/openembedded-core/log/?qt=grep&q=FKIE
This probably needs a proposal sent to architecture and oe-core mailing lists, since we would be looking for an exception to normal stable process.