Firefox > white space between the first 2 options in multi-select drop-down is vast

Steps to Reproduce :

1. Launch Firefox browser
2. Open CMS application
3. Go to Experience manager perspective
4. Open document with multi-select option
5. Open right side panel
6. Click multi-select drop down

Actual result : White space between "select all" and "Deselect all" is vast

Expected result : UI should be normal like in chrome

Screen recording : Recording