can't Tab from To field to Subject field
I'm running Geary from git mainline on Ubuntu 20.20.
In the message composer, after I fill out the To: field I can't press Tab to jump to the Subject field. If I press Tab once, the focus moves to the "..." button; when I press it again, the focus seems to go somewhere else (it's not clear where). This makes it awkward to enter a new message from the keyboard.