cannot add multiple labels in a page (in FireFox)

Issue Summary

cannot add multiple labels in a page (in firefox) from the label icon.
The issue occurs only in Edit mode.

 

Environment

Confluence Cloud

Steps to Reproduce

1. Edit a page
2. Click on "Add Labels" button
3. Type label name into the box
4. Click "Add"
   Then cannot type another label name in the box (keeps on losing focus)

Expected Results

After adding one label, user cannot type another label name in the box (keeps on losing focus)

Actual Results

User should be able to add multiple labels.

Workaround

Use other browser or add a label in view mode instead of edit mode.