Contact groups are created twice, contacts duplicated

[renestalder]

Apart from the app crashing all the time when trying to sync (without the error screen appearing. Just completely shutting the app down), I can't the app get to work in a way it doesn't sync the contact lists twice or duplicates contacts in the same address book. I removed all other contact books and calendar accounts, but the first sync after setup of etesync always crashes, then the second sync pulls everything a second time and duplicates all address books.

I think the iOS app would benefit from some additional testing and bug fixing on the latest iOS versions, as the guide itself is also outdated (Passwords & Accounts settings item does no longer exist).