Since updating Proxmox Backup Server to proxmox-backup-server 4.1.2-1, the scheduled Renew Certificate task (acme-renew-cert) runs indefinitely and does not renew the certificate.
Manual renewal finishes quickly (proxmox-backup-manager acme cert order).

proxmox-backup-daily-update.service shows:

2026-02-09T17:00:04+01:00 pbs1 systemd[1]: Starting proxmox-backup-daily-update.service - Daily Proxmox Backup Server update and maintenance activities...
2026-02-09T17:00:06+01:00 pbs1 proxmox-daily-update[1088]: thread 'tokio-runtime-worker' panicked at /usr/share/cargo/registry/proxmox-acme-api-1.0.2/src/init.rs:38:10:
2026-02-09T17:00:06+01:00 pbs1 proxmox-daily-update[1088]: AcmeApiConfig is not initialized!
2026-02-09T17:00:06+01:00 pbs1 proxmox-daily-update[1088]: note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Downgrading proxmox-backup-server from 4.1.2-1 to 4.1.1-1 resolves the issue.

Thank you both for your responses. Good to hear the bug is already registered and someone is working on a bugfix.

I'll leave this thread open until the bugfix is released.