journalctl not persistent AND 'Clock change detected. Flushing caches', 'Time jumped backwards, rotating'

System details:

WSL2: Ubuntu 24.04.1Win11: 23H2 build 22631.4037WSL version: 2.2.4.0Kernel: 5.15.153.1-microsoft-standard-WSL2

In 'journalctl' ('dmesg') and 'syslog' I see a lot of 'Clock change detected. Flushing caches.' and 'Time jumped backwards, rotating.' messages.This looks to have started shortly (nearly directly) after upgrading WSL2 Ubuntu 22.04.5 to Ubuntu 24.04.1.I did the upgrade on 2024-09-12 and got the "System upgrade is complete." message at 17:40.

I suspect this is causing journalctl not to log persistent.Even with /var/log/journal/ to be present and 'Storage=persistent' to be configured in '/etc/systemd/journald.conf'.Old journalctl messages look to be lost, even after a few hours.

What could be the issue?

The at 13:00 the oldest message showing up are from just over an hour ago:

$ journalctl Sep 15 11:35:31 DESKTOP-E6DGEM9 systemd-resolved[292]: Clock change detected. Flushing caches.Sep 15 11:35:31 DESKTOP-E6DGEM9 systemd-journald[50]: Time jumped backwards, rotating.

While the system is up for more than 15 hours:

$ uptime 13:00:46 up 15:35,  2 users,  load average: 0.10, 0.05, 0.01

So far I have seen the log to start with 'Clock change detected. Flushing caches.'

I tried to correct this by deleting the content of '/var/log/journal/' with:

systemctl status systemd-journaldsudo systemctl stop systemd-journald-dev-log.socketsudo systemctl stop  systemd-journald.socketsudo systemctl stop systemd-journaldsudo rm /var/log/journal/* -rfsudo systemctl start systemd-journald

but no change.

First time seen in '/var/log/syslog'

2024-09-12T18:13:41.079123+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:13:41.079123+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:14:12.855185+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:14:44.510248+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:15:16.254113+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:15:47.900499+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:16:19.571240+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:16:51.214299+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:17:22.709058+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:17:54.230828+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:18:25.739595+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.<snip>2024-09-12T18:26:18.238966+02:00 DESKTOP-E6DGEM9 systemd-resolved[269]: Clock change detected. Flushing caches.2024-09-12T18:26:18.240566+02:00 DESKTOP-E6DGEM9 kernel: systemd-journald[50]: Time jumped backwards, rotating.

Not sure if time synchronisation is involved.

NTP:

$ timedatectl               Local time: Sun 2024-09-15 14:10:00 CEST           Universal time: Sun 2024-09-15 12:10:00 UTC                 RTC time: Sun 2024-09-15 12:10:01                Time zone: Europe/Amsterdam (CEST, +0200)System clock synchronized: yes              NTP service: active          RTC in local TZ: no

$ timedatectl timesync-status       Server: 185.125.190.57 (ntp.ubuntu.com)Poll interval: 32s (min: 32s; max 34min 8s)         Leap: normal      Version: 4      Stratum: 2    Reference: B7A08584    Precision: 1us (-25)Root distance: 815us (max: 5s)       Offset: -2.699961s        Delay: 19.915ms       Jitter: 22.693ms Packet count: 1885    Frequency: -43.497ppm