8.20.8 menu scrolling issue

Issue Summary

This is reproducible on Data Center: yes

Customer is in the process of updating from 8.20.1 to 8.20.8. They've observed an issue with the web interface when opening the Issues menu and trying to scroll it when the list of issues/filters is long or when the browser is not in full screen. 

The menu drop down freezes on the page. When you scroll down the page  in background scrolls while the drop down is freeze in front of it. Also that prevents the customer from seeing all option on the drop down.

Environment:
8.20.8
I was able to recreate same behavior on 8.22.2

Notes:

Unclear when the bug was introduced.

Found a similar bug: https://jira.atlassian.com/browse/JRASERVER-71916

Steps to Reproduce

1. Make the browser window small
2. Click on Issue option on main menu
3. Scroll down, you will see the Issue drop down in front, not scrolling and the page in background scrolling

Note that this behavior occurs with all menu options, like Projects, Boards...

Expected Results

The drop down should be fixed on the main menu and you should be able to see all option on it when scrolling down.

Actual Results

The drop down freezes on the page and you can not scroll down until Manage Filter (last option on it)

Workaround

Use the browser on a bigger size.