I’m using ICSDroid (installed via f-droid) to sync my meetup.com, facebook.com, and kayak.com ICS feeds on a Moto X4, Android 7.1.1. After some time there are many duplicates of some events. It seems to affect all of the calendars. Right now I’m looking at 6 copies of the same event from Facebook, 4 copies of another event from Kayak, and 2 copies of an event from Meetup.
I’m not sure how to reproduce other than to provide my private URLs. Is there any steps I can take to try debugging the problem?