Xubuntu 20.04, systemd-journald high CPU usage

I'm not sure if this is the same issue as here systemd-journald high CPU usage because I was using Ubuntu 18.04 for these 2 years and everything was fine.

Yesterday, I've installed Xubuntu 20.04 (formatted only "/", "/home" left as is from Xubuntu 18.04). These 2 days I'm facing with slow work after some time. When I took a look at top output, I saw that systemd-journald eats 99%-100% of CPU. What's going on? How to fix it?

Some program is constantly generating log output.
To identify it, try journalctl -S -1hour and see how many lines are generated by which services in the last hour.
Then tell us what you found and if you can't fix it yourself, ask a new question "program xxx generates too much log output".