How to search/filter events in the logging admin panel with Nextcloud 20?


In Nextcloud 19 (and before that I believe) in the logging panel of the administration setting, we could search for something like “login failed” and see all (recent) occurrences of this type of event in the log.

In Nextcloud 20.0.7 it appears to not work anymore. It just tells me that nothing is found (anywhere on the instance) and the log stays the same.
Is there some kind of tricks to make it work or is it a bug ?
In the app center, we can still type an app name in the search bar, and it shows apps related to that name only, so it appears to work.

I am an admin on this instance, but I don’t have ssh access to the server (but I can ask stuff to the other admins if there is something to do).