cmd+V in customer portal's description/comment form doesn't work in Safari/Firefox

Issue Summary

When using cmd+V (MacOS) in Safari or Firefox (not reproducible in Chrome) to paste content into description or comment form of Customer Portal the content is not pasted. Context menu is highlighted though and the paste can be done by clicking the "paste" option with cursor.

It is unknown if the problem happens also on Windows computers.

Steps to Reproduce

1. Use Safari to access Jira
2. Access Customer Portal (<JIRA_URL>/servicedesk/customer/portals)
3. Open form for any request
4. Copy any content into your clipboard (cmd+C)
5. Use cmd+V shortcut to paste clipboard content into the description field of created request

Expected Results

The content appears in the description field

Actual Results

Nothing happens. The clipboard content is not present in the description.

Workaround

The content can be pasted by using "paste" option in the context menu (right click)