If you have a multi screen setup and assign the find track/channel to a keyboard shortcut, doing the keyboard shortcut while on the 2nd screen (or any other screen that is not you 1st screen) will make the find box appear in the 1st screen only. That behavior used to be fine in C7.5.
-put project window on 1st screen and mixer on 2nd screen
-assign a keyboard shortcut to find track/channel
-put you mouse on the second screen (anywhere on the mixer)
-do the keyboard shortcut
-notice the find box will appear on the 1st screen