Does anyone use a different contacts app on Android please? The problem I have is that I now have multiple duplicate contacts. Google wants to sync the contacts with its servers and DavX with Nextcloud creating two contacts and it is frustrating. When I make a change I never know where that change is stored and find sometimes the change is deleted.
Sorry I don’t quite understand what the issue is? Does the Contacts app on your phone actually duplicate new entries, or did you import all your Google contacts into Nextcloud, and now it simply shows the entries from both accounts? The latter is normal, if both contact lists (Google and Nextcloud) are active in the contacts app.
A solution could be to hide / disable the Google contacts list and set the Nextcloud / DAVx Contacts list as the default for new contacts. Or you could even delete the contacts in your Google account completely and / or disable the contacts sync with Google after importing all contacts into Nextcloud (that’s what I did). I think it makes little sense to have the same contacts stored in two places, unless of course you’re still using some of the Google services like Gmail and want the contacts to be available in the Gmail web interface.
But again, if you have multiple contact lists added to your phone it is normal that you have to actively choose in which contact list you want to store new contacts, and in which contact lists it should search for existing contacts, just like with multiple calendars. I don’t see how this could be solved in a better way, and it won’t work fundamentally different in another contacts app.