Notifications: display issue with the Twenty Twenty theme

When Jetpack is active the Twenty Twenty primary menu breaks when selecting menu items that cause hidden menu containers to appear:


This does not happen when Jetpack is not active.

Further, when the WordPress.com toolbar feature is active, notifications do not fully expand:


### Steps to reproduce the issue

1. Make sure Twenty Twenty is your active theme and only Jetpack is active
2. Activate WordPress.com Toolbar (Jetpack > Settings > Writing )
3. Change header and footer background color so the behavior is easier to spot (Appearance > Customize > Colors)
4. While still logged in, visit the site's homepage and select Menu or Search from the primary menu
5. Watch the primary menu break as pictured above
6. Again, while still logged in, select the WordPress.com notification bell icon
7. The notifications container does not fully expand as pictured above

#### What I expected

The theme primary menu should not change when hidden menus appear. And notifications should fully expand.

This was originally reported in 2691533-zen. I was able to test and confirm the bug on my test site.