Shift Forward Slash
I SWEAR that if I was working in the Effects panel .. the Effects panel active ... I could press Shift Forward Slash to fit my comp viewer to All. Now I can't do that. In order to get Shift Forward Slash to work I have to activate the timeline panel or the comp viewer.
I know this has to have worked in the past - I apparently have the muscle memory of using it when the Effects panel is active because I keep trying to invoke it and my "why isn't this working" frustration is fairly recent.
Thanks for filing this bug. This is a known issue in After Effects 18.4. If the Composition or Timeline panel are not focused, keyboard shortcuts for zooming the active viewer panel do not work.
This has been in fixed in After Effects Beta (v22.1). Please install the latest build to confirm the fix. Apologies for the disruption.