Unblocking a number not appearing in iPhone's blocked contacts list

I cannot text a friend whose number has "Block Caller" in red in the contact's file, but this number does not appear when I click on Settings>Apps>Phone>Blocked Contacts. I thought if I deleted the contact and re-entered the contact, maybe it would not be blocked. When I try to send a text to this number, here's what I get in return:

Free Msg: Unable to send

message - Message

Blocking is activ

How do I unblock this number, when the number doesn't show up in blocked contacts?

(I'm using an iPhone 14plus, IOS 18.6 (new update tonight - 7-30-25)

[Re-Titled by Moderator]

Original Title: Unblocking an unblocked number