F6 can not be used to step over when debugging, if a search operation has been performed

In QT Creator, compile a project, which has some errors.
F6 key allows navigating to the next step.
Search for a string in the files
Now F6 allows navigating between the different found references.
F6 cannot be used any more to navigate to the next step.

Workaround:
Closing the output panes window keeps stepping through the found instances.
Selecting another output pane (such as 1. Build issues, 3. Application Output) assigns F6 again to stepping through the code.