Duplicity S3: Error when calling the HeadBucket operation

I'm trying to get Duplicity to work with OVHcloud's S3 offering.
I've set up an S3 container, and it works when I use "s3cmd":

me@pc ~]$ s3cmd ls
2023-05-07 16:02 s3://backupcontainer-pc

However, when using [duplicity (version 1.2.2), I run into an error:

File "/usr/lib/python3.11/site-packages/botocore/client.py", line 960, in _make_api_call
raise error_class(parsed_response, operation_name)
botocore.exceptions.ClientError: An error occurred (400) when calling the HeadBucket operation: Bad Request

This is the command I use (altough I add many more --include/--exclude parameters):

duplicity --verbosity Debug --no-print-statistics --include /usr/local --include /root --exclude ** --asynchronous-upload --s3-region-name WAW --s3-endpoint-url https://s3.waw.io.cloud.ovh.net / s3://backupcontainer-pc

When running the command, AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY are set using the same values which work with s3cmd.

Any ideas?