[5.x]: Matrix fields' entry type group headings disappear upon closing the type selector, if the search input is visible #17581

What happened?

Description

If the search input is visible in Matrix fields' entry type selectors and there is more than 1 entry type group, the group headings become hidden when the selector's disclosure menu closes and do not re-appear when the selector is re-opened.

This only happens if the search input is visible (i.e. there are more than 5 entry types in the field).

I'm not able to reproduce this on 5.8.4, only on 5.8.5.

Steps to reproduce

1. Have a Matrix field with at least 5 entry types and at least two entry type groups.
2. Click the "New entry" button to open the type selector disclosure menu.
3. Close the selector menu, and click "New entry" again to re-open. Notice that the group headings are no longer visible.

Expected behavior

Actual behavior

Craft CMS version

5.8.5

PHP version

No response

Operating system and version

macOS 15.5, MS Edge 138.0.3351.55

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

None