Labels broken when multiple projects are open

[SteveDaulton]

Bug description

On switching to another open project, the creation or editing of a label is broken.

Steps to reproduce

1. Create two open projects with one audio track and one label track.
2. Switch from the active project to the other project
3. Edit a label

Expected behavior

The label is edited.

Actual behavior

The keys pressed are interpreted as commands. For example, if you try to enter an "r", the project starts recording.

Audacity Version

current master / alpha / nightly build

Operating system

macOS

Additional context

Reported on the Audacity Forum

Original report was for macOS. Bug confirmed on Linux.