wp_cf7dbplugin_submits table primary key

I am unable to restore a database backup due to something related to the CF7 plugin and I was asked by my host, WP Engine, to reach out to the developer of this plugin and ask about the wp_cf7dbplugin_submits table’s lack of a primary key. Is this working as intended?

Here is their note to me in it’s entirety:
Firstly, what I’d like to have you do is reach out to Contact Form 7 plugin development directly regarding the wp_cf7dbplugin_submits table. Normally, I can’t think of a reason for a DB table to not have a primary key set up, but since I’m not a plugin dev, I’m not sure if that’s intended. I’d like to have you confirm with them whether that table is working correctly or not. If it’s *not*, they can likely help you get it fixed, after which any new DB restores should work fine. But if they come back and say “yes – that’s working as intended,” then we will need to check into why DB restores aren’t working on our side, which is what would require some further manual troubleshooting on a staging site.