Steps to reproduce the issue

The file plg_system_jooa11y.ini has escaped single quotes ' in 3 lines :
Line 63: PLG_SYSTEM_JOOA11Y_PANEL_STATUS_12="The item you are trying to view is not visible; it may be hidden or inside of an accordion or tab component. Here's a preview="
Line 83: PLG_SYSTEM_JOOA11Y_LINK_URL="Longer, less intelligible URLs used as link text might be difficult to listen to with assistive technology. In most cases, it is better to use human-readable text instead of the URL. Short URLs (such as a site's homepage) are okay."
Line 91: PLG_SYSTEM_JOOA11Y_NEW_TAB_WARNING="Link opens in a new tab or window without warning. Doing so can be disorienting, especially for people who have difficulty perceiving visual content. Secondly, it is not always a good practice to control someone's experience or make decisions for them. Indicate that the link opens in a new window within the link text."

Testing
Line 91 used as example
Set the accessibility test setting Links (Advanced) to on.
Insert a link into an article and set it to open in a new window e.g. Test Link
Save article and click on Accessibility Check
An accessibility warning appears next to the link. Click on it

Expected result

Text shown with correct apostrophe and escape character (backslash) not shown

Actual result

Text shown with escape character

Additional comments