Deleted libraries don´t get cleaned automatically

I run Seafile 7.0.5 on a raspberry pi 3 (Raspbian Jessie-lite, lates updates on 2020-03-31) with nginx and mysql for about 3 years without any major problems. About half a year ago I deleted some libraries. I expected them to be fully deleted (trash bin logic) after 30 days without recovery. Today I checked the web admin panel of my Seafile server and I noticed that all those libraries are still in the trash bin and probably recoverable (didn´t test).
I´m confused because the UI is telling me libraries deleted 30 days ago will be cleaned automatically (see attached screenshot).
Q: Is this a bug or did I do something wrong?

It’s not a bug - it’s a feature. To free up the disk space you’ll have to start the garbage collector.
You can read how to do that in the manual:
https://download.seafile.com/published/seafile-manual/maintain/seafile_gc.md

Just to clear up ambiguities. The seaf-gc.sh is already running every night at my server to clear up deleted files and make room for new data. As far as I´ve checked there is significantly less seafile-data after I´ve deleted a bunch of files + ran the seafile-gc at night.
I still don´t get why Seafile still shows those deleted libraries in the admin-panel after 30 days. I´d get it if they wouldn´t be completely deleted at garbage collector level but they should be removed from the trash bin in the web panel (as the mentioned tip says) in my user understanding. Not sure if that is still a feature.

Ok sorry, then I really got you wrong.

Looks like its a bug. Shouldn´t this be fixed? While I use seafile “productive” I´m not confident enough to press “cleanup” in the Webinterface. It is weird that I´m the only one who encounters this problem regarding the false promise “auto delete after 30 days”.