This search returns a hit for "testify" in John 1:1 (NIV), even though the word is not in the verse:

Footnote B in this verse refers to "Jn 17:5; 1 Jn 1:2", and 1 Jn 1:2 does have the word "testify."
Has something gone wrong, so it is now returning verses that footnote other verses that contain the search term?
(NIV resource was updated today.)