Rich text editor unable to set Polish character 'ś' in MS Edge using Visual Mode

Issue Summary

After upgrade JIRA from v7.13.8#713008-sha1:1606a5c to v8.6.1#806001-sha1:b7cf80b
Some user giving us feedback about using Alt+s shortcut when editing the description, adding or editing comments it saving their actions in Rich Text Editor Visual mode.
In Poland Alt+s is using for "ś" it's one of the diacritical marks.

Steps to Reproduce

1. On Windows using Internet Explorer or Microsoft Edge
2. Install keyboard layouts: Polish (Programmers)
3. Choose Visual mode.
4. While editing description or comment press AltGr + s to get character 'ś'.

Expected Results

Character 'ś' is showing upon pressing AltGr + s.

Actual Results

It's blank and seems likely to have a refresh effect. However, it works fine in Firefox and Chrome using Visual and Text mode.

Workaround

There is no workaround at the moment. User can use Firefox and Chrome that has the correct behavior.