Never mind… I think i have fixed it for now. I went into Google Calendar in the browser, searched for each event and deleted all recurrences. Within a couple of update cycles on the MagicMirror the events disappeared.
I’ve tested my config with several other RSS Feeds and I can see the problem only with the feed listet in the description, all other feed works fine .
I have no idea what happens. Do I have any further log informations for debugging the situation??