Why is this comma wrong?

"Another pattern, that regularly appears, is a Not Found response that queries the database...".

I think this is incorrect but I'm not sure.

I think the correct version should be:

"Another pattern that regularly appears is a Not Found response that queries the database"

However, what rule is coming into place here? I originally said it was because "that regularly appears" was a restrictive appositive, but I don't think that's right now.

Personally, if you wanted to keep your phrasing the same, I'd go for:

Another pattern that regularly appears, is a Not Found response that queries the database...

However, as previous commenters have said, another pattern that regularly appears is a bit awkward, try:

Another regularly appearing pattern