Weird menu alignment problem only shows up on release

[krivard]

Actual behavior

The release preview for v3.0.8 shows a gap between the menu header and menu body:

however this gap does not appear in the dev branch preview. The only commit that's in the v3.0.8 release branch and not in dev is a290a41, and the only thing it contains is the version bump for www-main.

Expected behavior

• Menu is connected to menu header
• Release appearance should ~match dev

To reproduce

either

1. go to release preview
2. mouse over a menu header
3. compare with same in dev

or

1. close PR for v3.0.8 & delete the branch
2. run the "create release" action from dev with patch
3. load resulting release preview
4. mouse over a menu header

Severity

3 -- not currently showing up in production, but eventually (2 weeks?) we'll want to release some pending content additions.

Additional context

OS/Browser: macOS 12.2.1 / Chrome 99.0.4844.51

At first I thought this must have been an unintended consequence of the uikit update, but if that were so, I'd expect it to also be broken in dev. 😕