Setting Up Cloudflare R2 - Error On Backup with Unraid

I’me setting up Duplicacy > R2 (S3 compatible mode) and have been able to connect, see buckets and move some smaller appdata folders to R2. The larger backup always fails with the following error. I’ve checked, rechecked and recreated my access creds, so any other suggestions would be appreciated.

Running backup command from /cache/localhost/1 to back up /OwnCloud/jl/files
Options: [-log backup -storage Unraid-Backup -threads 4 -stats]
2023-01-15 07:44:57.980 INFO REPOSITORY_SET Repository set to /O/jl/files
2023-01-15 07:44:57.980 INFO STORAGE_SET Storage set to s3://us-east-1@698060965271c7.r2.cloudflarestorage.com/coldfiles/chunks
2023-01-15 07:45:03.329 INFO BACKUP_START No previous backup found
2023-01-15 07:45:03.329 INFO BACKUP_LIST Listing all chunks
2023-01-15 07:45:03.370 INFO BACKUP_INDEXING Indexing /OwnCloud/jl/files
2023-01-15 07:45:03.370 INFO SNAPSHOT_FILTER Parsing filter file /cache/localhost/1/.duplicacy/filters
2023-01-15 07:45:03.370 INFO SNAPSHOT_FILTER Loaded 0 include/exclude pattern(s)
2023-01-15 11:08:36.042 ERROR UPLOAD_CHUNK Failed to upload the chunk 7bfc7ef8bc91e199dee43848970d6768e27d7: SignatureDoesNotMatch: The request signature we calculated does not match the signature you provided. Check your secret access key and signing method. 
	status code: 403, request id: , host id: 
2023-01-15 11:09:14.690 INFO INCOMPLETE_SAVE Incomplete snapshot saved to /cache/localhost/1/.duplicacy/cache/Cloud-Backup/incomplete_snapshot
Failed to upload the chunk 885fef48c1e7bfc7ef8bc91e199dee43848970d6768e27d7: SignatureDoesNotMatch: The request signature we calculated does not match the signature you provided. Check your secret access key and signing method. 

(stripped some data out of the paste from above)

Can you try to add the -limit-rate option to reduce the upload speed (or change the number of threads to 2)?