How can I debug random exits on watchtower

[thelfensdrfer]

Most of the time watchtower runs great in the background and updates my images. Sometimes it just exits (randomly, not during an update):

watchtower-1  | time="2024-02-07T06:00:13Z" level=debug msg="No post-check command supplied. Skipping" container=/grafana-cadvisor-exporter-1
watchtower-1  | time="2024-02-07T06:00:13Z" level=debug msg="No post-check command supplied. Skipping" container=/grafana-node-exporter-1
watchtower-1  | time="2024-02-07T06:00:13Z" level=info msg="Session done" Failed=0 Scanned=14 Updated=0 notify=no
watchtower-1  | time="2024-02-07T06:00:13Z" level=debug msg="Scheduled next run: 2024-02-07 07:00:00 +0000 UTC"
watchtower-1  | time="2024-02-07T06:00:15Z" level=debug msg="Valid token found."
[...]
watchtower-1  | time="2024-02-07T06:11:35Z" level=debug msg="Valid token found."
watchtower-1  | time="2024-02-07T06:11:40Z" level=debug msg="Valid token found."
watchtower-1  | time="2024-02-07T06:11:43Z" level=info msg="Waiting for running update to be finished..."

This happens on multiple different hosts. Sometimes at roughly the same time, sometimes not. This is a different host from today, both have the correct time.

watchtower-1  | time="2024-02-07T06:14:54Z" level=debug msg="Valid token found."
watchtower-1  | time="2024-02-07T06:14:59Z" level=debug msg="Valid token found."
watchtower-1  | time="2024-02-07T06:15:04Z" level=info msg="Waiting for running update to be finished..."

How can I debug this issue? The debug mode is already enabled but it does not output anything. The other containers are running without stopping.