Deleted events are not deleted from activity pub feed (?)

On Mobilizon version 1.3.2 Deleted events disappear from the instances feed in the mobilizon interface/frontend. However, the posts are still visible when looking at the profiles feed e.g. via a mastodon client.

This is annoying at least for the following reason: spammer events still pop up in the timeline of fediverse users. this bug was also described in the general feedback on moderation #686 (closed)