I have a similar or perhaps the same issue. I just switched from a P6a running GOS to a P9. When I installed the latest GOS build on the P9 last week, everything seemed normal/typical to me. I didn't both to start configuring the phone until a couple of days ago, which is when I realized that I couldn't get contacts to import or sync using the default Contacts app.
From the empty Contacts screen, when I click the option to "ADD ACCOUNT", I'm taken to "Add an account" and an otherwise blank screen. However, when I go Settings > Passwords, passkeys & accounts, the account that I wish to select is there (a DAVx5 account to sync my contacts).
Back on the Contacts screen, when I click the option to "IMPORT", an "Import contacts from" modal opens with the option to select a .vcf file or SIM card. If I select the vcf file option, I can open the file folder with my contacts.vcf that I've staged to import. However, clicking on that VCF file produces the helper/error message "Couldn't import vCard. The format isn't supported."
I did get contacts sync'd using DAVx5 and Fossify Contacts, but I'd definitely prefer to use the default contacts app.
If this is just something I'm doing wrong (wrong setting or permission of some sort), please let me know. If it's a bug, fingers crossed that it's an easy patch.
Also, I've been using GOS for about a year, I'd guess. This is my first post, although I frequently read and try to learn here. I want to thank everyone in the forums for your insights. And I especially want to thank the GOS team! This software is amazing; your work is so desperately important and relevant right now. It seems apropos to say that I'm thankful for you ;-)