Gmail: Multiple inboxes sections

I use Firefox v77 under Linux and I have the following issues with Multiple inboxes shortcuts.

1. When I move the focus to previous or next inbox section with the tilde (~) or the backtick (`) shortcuts, the webapp does not scroll to a position where the section title is visible, but stops to the first row of the section. So I do not know in which section I am. I need to use the scrollbar to show the upper part, which makes the shortcuts unusable. This happens when there are more than a few items in the section.

2. When sections are collapsed, the shortcuts to reach them do not work.

3. I can't find a shortcut to expand/collapse the inbox sections.

Do you experience this too? Any fix?

PS: Point 1 does not apply to Chromium.