Running Nextcloud 24.0.6 from a web browser. It is hosted by cloudamo.com. I have pre-existing recurring entries in the calendar app. I update one of them to occur on a different date (a certain day each month). I select the date. Click on OK. Then select the option to update this and all future occurrences. The updated entry completely disappears from the original date, and does not appear in the new date. The other (future) entries are not updated.
This server is also connected to the Samsung calendar app on my cell phone. It doesn’t have this problem.