JSON error prevents the 'Edit' popover icon to be displayed in some cases

STEPS TO REPRODUCE

1. Create a Docker instance of XWiki 13.6 (I've reproduced the issue only on Docker apparently)
2. Login as Admin
3. Go to a Live Data table with entries containing a link (e.g.

   <server>bin/view/Sandbox/?viewer=children

   or

   <server>/bin/view/WikiManager/

4. Mouse hover over an editable link of an entry (e.g. from 'Title' column of Children of Sandbox Live Data table)

EXPECTED RESULTS

The popover 'Edit' button is displayed properly with its icon.

ACTUAL RESULTS

The icon is missing from the 'Edit' popover button. No error in XWiki console.

However, in browser's console there are some JSON related errors:

Uncaught SyntaxError: Unexpected token '<'

GET http://localhost:1113/xwiki/rest/wikis/xwiki/iconThemes/icons?name=edit 404

SyntaxError: Unexpected token < in JSON at position 0
(anonymous)	@	XWikiIcon.vue:100
...

Please see the attached screenshots.