For some reason iode/(Brax?) elected to include Fossify Messages as the default SMS text app, but went with only the AOSP Contacts app instead of the corresponding Fossify Contacts app. IIRC the AOSP Contacts app (and Google’s closed fork) is still stuck on vCard version 2, while iPhone moved to version 3 a long time ago.
The good news is that the Fossify Contacts app will import/export vCard version 4 format (and earlier versions). This also comes in handy when you want to transfer contacts from Thunderbird/Betterbird to your phone, as Mozilla upgraded the Address Book vCard import/export format from v2 to v4 awhile ago.
The Fossify app suite as a whole also interoperates better with all its own messaging-related apps installed …
So if you need to import native vCard format v4 then install Fossify Contacts and import the cards from there. It Just Works – though some differences between v2 & v4 mean that you may need to recategorize some of your imported phone numbers and other contact info.
You won’t need to use Fossify Contacts as your default app for Contacts. But if you want to do that then you will probably also want to install the Fossify Phone app and make it the default Phone app as well.
(I’ve done all this on other custom ROMs but I’m still waiting for the Wi-Fi issues to be ironed out on the BraX3 before I make any changes to the installed apps.)