Search on my iPhone 7plus us not working on my notes or text messages

Thanks for the additional information. Are these all stored in iCloud? It could be that there is restricted access for the search to look in the iCloud items. You might try going to Settings>Tap User at top>iCloud, then disable the notes, then enable and see if the issue persists.

It may be worth a shot to backup, then restore your phone from the backup to see if that fixes the issue.

If you go to Settings>General>Spotlight you should be able to see if Notes and Messages have been turned off from spotlight searching. Or do you mean the search within those specific apps is not working?

Does the search bar not even appear? or when you type in it, nothing happens?