Working with V. 6.22.7 on Pixel 6 with Android 14 (grapheneOS)
In my case the app displays only a few contacts that are store in the device.
No DAVx contact is displayed. So I exported to VCF file.
The exported VCF file contains also dummy versions of my DAVx contacts (even though they are not displayed).
(I did not check the content of the file. So after reimport of the VCF file with the standard contact app to the DAVx account all my DAVx contacts are duplicated.)