STEPS TO REPRODUCE

1.a. Open gnome-clocks, without any clock (city) available, on tab "World"
1.b  Open gnome-clocks, without any alarm, on tab "Alarm"
2. Try to navigate using only the keyboard

EXPECTED OUTCOME

You can navigate on the buttons of the top panel, to among

ACTUAL OUTCOME

Pressing tab of arrows doesn't move to anywhere. Not clear focus

NOTE:

Among other things not keyboard navigable (so accessible), are the label "Select New to add X"

As soon as you add an Clock/Alarm, the top panel became navigable (so accessible). Sometimes I can even focus on the clock/alarm itself.