Paste clipboard into search field: cannot search

If I enter the search field and paste something in, the search button is deactivated.

Do you use an iPhone or iPad?

ipad pro 9.7

Confirmed on iPad Mini 2 and iPhone 6.

This is a bug in Appleā€™s implementation of UISearchBar. The search is still immediately run and the results shown but the Search button is not enabled until you type or delete at least one additional character. So: not serious.