TOC Links Stop Working After Changing Heading Title

Hello,

I have the latest version of this plugin, WordPress, and the theme I use.

My problem:

1. I changed the titles of my headings and cleared cache.
2. The new titles and links are correctly displayed in the Table of Contents.
3. However, the new title/link does not work. Nothing happens when I click on it.
4. The links for the heading titles which I did not change still work fine.

What I have already tried:

1. Disabling and re-activating the plugin.
2. Making sure there isn’t a conflict between TOC’s global settings and specific post or page settings.

Anyone familiar with this problem and how to solve it?

Thanks.