BYOC S3 Export Fails with 403 for Legal Hold Digital Channels

Looking for advice on resolving a 403 Forbidden error during bulk exports for legal discovery. The issue occurs specifically when exporting WhatsApp transcripts to a BYOC S3 bucket. The IAM role attached to the Genesys Edge has s3:PutObject permissions, yet the job fails immediately.

“Ensure the IAM role grants write access to the target bucket and its prefixes.”

Verified permissions via AWS CLI. The same flow works for voice recordings but fails for digital channels. Is there a specific metadata tag missing for BYOC digital exports?