So the library mentioned in the documentation (Particle AmazonS3Client) must have been failing silently on buckets made after September 30, 2020 when path-style urls were deprecated in favor of the virtual-hosted model[1]. It took me a while to figure out what was going wrong because I was just getting nulls in response to my requests. I’ve updated the code to reflect this change and also updated places where Spark was used instead of Particle.
Hope to save people some headaches.
[1] Amazon S3 Path Deprecation Plan – The Rest of the Story | AWS News Blog