I had similar here, symptom was the same as yours:
https://discourse.mailinabox.email/t/aws-s3-policy-blocking-duplicity-restore-solved/10216/2
Cause was a malformed URI
I had similar here, symptom was the same as yours:
https://discourse.mailinabox.email/t/aws-s3-policy-blocking-duplicity-restore-solved/10216/2
Cause was a malformed URI