Steps to reproduce:

1. Open any file with Qt Creator editor and press Cmd + F to open finder.
2. Open macOs application (Mail or Notes).
3. In Notes press Cmd + F in any notes and put some word there - hit enter.
4. Get back to Qt Creator and click on the search field.

This happens also with Maill.app when you search for email using search in the top right corner.

Expected: Field remains unchanged.

Actual: The search field is auto-filled with the phrase or word search in other application. 

Reproducibility:  100%