Hi, this is Beda, I will help you with this.
1. Please change the theme.
Yes, this sounds shocking at first, please let me elaborate properly and inform you why, how and when.
- The Toolset Starter theme is deprecated.
- We deprecate this Theme because of several reasons:
1. It uses customized styles
2. It is not Toolset Content Layouts Ready
3. It is not using default WordPress API but was created only and solely to show users how you can use Toolset on a Theme that is fully integrated, which is something that became unnecessary nowadays.
4. It is and was not Toolset's main goal to enter in Theme development, but instead Plugin development and cooperation with 3rd Party Theme developers
- As solutions, use a custom post types ready theme as shown here:
https://toolset.com/documentation/recommended-themes/. Or, you can use any other theme that uses the_content().
Or, if you need to design the entire template with Toolset Layouts - then you need a custom theme such as this very thoughtful example here:
hidden link
This last theme is an example I made for the purpose to teach how to create a custom boilerplate of a Theme that not only integrates Toolset but as well works without it, or mixed (with and without Toolset on different content).
When and how you should update, is up to you, but it's suggested to do this ASAP, and I suggest to follow as outlined:
- grab your current site and duplicate it on a staging site
- if you need Toolset Layouts to design the templates completely, install the Minimax Theme
- if not, install any other theme
Check the front end, and add eventual CSS to the Theme so to adjust the appearance.
You can as well proceed using the Starter Theme, but we cannot push more updates to it, as it's deprecated.
Now to the issue you report.
1. The Checkbox is included automatically if you add a call to comments_template(); to your Theme's single post PHP template.
2. The Starter Theme uses comments_template(); as well, so I do not see why this should not work, but it does not.
There is a major WordPress issue as it seems to me:
https://wordpress.org/support/topic/read-this-first-wordpress-4-9-master-list/#post-9687602
https://wordpress.org/support/topic/no-comment-form-cookie-consent-on-wp-4-9-6/
If you ask me, WordPress did not ship a fully working update, as the users confirm in the very support tickets, but it seems they do not yet know about this or do not know how to replicate it.
In fact, after clearing cache several times and as well waiting the suggested hour, solved the issue.