I hadn't tried this before I read your post. I opened the contacts app, selected a contact and selected share as a vcf. I chose the Samsung messages app. I selected the contact to share it with it sent and received with no issues. I did the same and chose share as a text and had no issues.
I opened Samsung messages, used the attach file option and chose contact. I selected the contact and chose share as a vcf file and as a text. Both sent and received with no issues.
I'm running Samsung messages app version 10.1.40.77 and contacts version 10.2.20.16.
We have different models and are running different app versions but the option to share contacts using the messages app should work the same. VCard files and text are both supported with the messages app version I'm running.
I would try clearing the cache for the messages app and the contacts app. It's a harmless trouble shooting step that sometimes will resolve issues.
You might also try backing up your messages to Samsung cloud and clearing the messages app data. Set the settings back up and restore your messages.
For the contacts app I would use the the option in manage contacts to export your contacts as a vcf file to internal storage just to be safe. If something goes wrong with syncing them to your Google account or Samsung account as the default backup location then you can always use the option to import them using the the vcf file you exported to internal storage.
It could be a glitch that started with a recent security patch and waiting for the next update might be a good idea if you're not comfortable with clearing the cache and data.
Galaxy S9 SM-G960U
Security Patch Level
December 1st , 2019