Stopped working – and logs can’t be deleted

Hello.

I have a multisite.
I have this plugin activated on one of the subsites.
The plugin tracked logins for 2 days, and now has suddenly stopped.
No login info is now updated on the user list.
I’m 100% sure of that, because I have some additional account, apart from the admin account I use, and when I log in with those accounts, nothing is updated.

When I go into the settings page, I click on the buttons to delete the logs, it says that there are no logs to delete. But this can’t be true, because it still shows the last login time for the users on the user page (last updated 2 days ago).

Even if I deactivate, then delete the plugin from the Network site, then reinstall and reactivate, the logs are still there. They were not removed when the plugin was removed.

Any idea what’s wrong, and how to fix it?
Thank you.

PHP Version: 7.3.14
MySQL Version: 5.7.29