Table of Contents (TOC) plugin - Admin strings not translated on the front end

Overview of the issue

When using the Table of Contents (TOC) plugin, you are able to translate admin strings such as Heading text, Show text or Hide text, however their translations do not appear on the front-end.

Workaround

Please, make a full backup of your site before proceeding.

1. Open the …/wp-content/plugins/table-of-contents-plus/toc.php file.
2. Look for line 37.
3. Replace

   // do the magic
   $toc_plus = new TOC_Plus();
   

   With

   // do the magic
   add_action( 'init', 'toc_init' );
   function toc_init() {
       global $toc_plus;
    
       $toc_plus = new TOC_Plus();
   }