Accessibility issue: 'Tab' key navigation going off issue create screen in Customer portal

Issue Summary

Accessibility issue: 'Tab' key navigation going off issue create screen in Customer portal

Steps to Reproduce

1. Login as a service desk customer to Customer Portal
2. Open 'create issue' screen
3. Start pressing 'tab' key on the keyboard. Notice that the 'tab' focus cycles through the options on the page and browser controls
4. Add a few comments by using keyboard only and keep cycling through the page options via 'tab' key

Expected Results

Tab focus should consistently cycle through the issue screen options and browser control elements by pressing the 'tab' key the same number of times.

Actual Results

Tab focus disappears after "Jira Service Desk" logo goes in focus, and then seemingly disappears.
I.e. user hits 'tab' - nothing happens, 'tab' again - nothing. And then after clicking 'tab' multiple times, the focus comes back.

The following HTML elements are added to the page HTML every time an action such as saving a comment is added:

<div class="attach-screenshot-paste-catcher" contenteditable="true"></div>

This is the element where 'tab focus' goes to. Since the element is multipled every time a comment is made or action is done, next time user cycles through the option, it needs extra 'tab' to get the focus back.
While the elements can't be seen on the screen, it's there in the HTML and is where the 'tab' focus goes.

Workaround

Keep pressing 'tab' key for as many times as required to get the focus back