How do I manually block a phone number on iPhone SE (3rd Generation)?

Suzan52 wrote:

You're right! Thank you!!

That's the type of error I would make. I'm (obviously) going to have to pay attention to stuff like this.

We've all done that!

Any idea why I can't seem to manually Add New phone number directly to the blocked contact list?

No, I don't. You shouldn't have to add the number to contacts in order to block it. If you tap on the "I" you should get this screen for a number that isn't in your Contacts:

Is that not what you're seeing?

Again, there should are no need to add the number to Contacts in order to block it.

Are you scrolling all the way to the bottom of the page?

You're getting that popup because you're pressing and holding on the "i", not tapping it. If you tap on it, you should get to the proper page.

Any idea why I can't seem to manually Add New phone number directly to the blocked contact list?

Because the "new number" would not automatically update in Contacts. Get the Contact edited first with the correct new number. Then.....block the Contact(s) that you wish.