Reporting what appears to be a bug in the native S3 backend's SigV4 signing. Happy to provide additional logs or test a patch. Details below.
Version: proxmox-backup-server 4.2.5-1 (also reproduced on 4.2.4-1)
S3 provider: StorageFactory.io (MinIO/RADOS-based), via Curanet
Summary: PBS...