Synchronize contacts using DAVx5

Using /e/OS Applications
1

I can’t sync my contacts properly.
Here’s what I’m doing:

After setting up DAVx5, I’m shown the following options for creating new contacts:

Screenshot_20260417-184225_Kontakte
Screenshot_20260417-184225_Kontakte1116×2484 131 KB

Result when selecting “Device”: The data isn’t backed up.
Result when selecting the other option: The backup works.

Screenshot_20260417-190622_Kontakte
Screenshot_20260417-190622_Kontakte1116×2484 164 KB

But when I add a contact via WhatsApp, “Device” is automatically selected as the storage location.

Screenshot_20260417-184449_Kontakte
Screenshot_20260417-184449_Kontakte1116×2484 160 KB

Result as above: The data is not backed up

Question:
Is there a way to configure this so that WhatsApp contacts, which are saved in the phone book, are also backed up?
I suspect others have this problem too. Is there a solution?

It doesn’t necessarily have to be DAVx5…

2

Device = SIM card. Sounds like you don’t want this.

Contacts > 3 bar top left Menu > Settings includes

Default location for new contacts. You may have that set to Device? When you want Contacts (user_descriptor). Or in your case “default (user_descriptor)” if you prefer the DAVx5 method

Native Contacts thread How to unify and sync Contacts + Webmail contact lists in /e/OS?

3

Re 1.
Contacts are no longer stored on SIM cards.

Re 2.
In WhatsApp, I have the option to save the contact to my device or manage it directly through WhatsApp.

With option 1, the entries appear in my phone’s contacts.
With option 2, they do not appear in my phone’s contacts.

The solution would be that I wouldn’t have to import a contact received via WhatsApp with the press of a button, but instead should add it manually to my contacts.
I can’t imagine that no one else has noticed this while using WhatsApp. How have others solved this problem?