You can Whitelist your contact list on the iPhone.
Go to the Protect tab and scroll all the way down to see the option to whitelist.
You will need to make sure the number in question is in your contact list for it to go through.
Make sure you don't close the app after this. A call list update will have to go through for the change to take effect.
If whitelisting doesn't seem to be working and your contacts are still blocked please try the below steps:
In the Protect tab, make sure the “whitelist my contacts” option is ON, then tap on Neighbor Scam Protection and remove the numbers you share with your contacts and then re-add them.
You remove a number from that screen by swiping left on a number then tapping Delete.
A call list update will have to go through after you do this so make sure that you do not close the app before the call list update happens.