Refer to the post Before Upgrading to Version 2.x for details regarding the source of this issue.

To fix the missing paragraphs and retain the HTML-editing features added with version 2.x, edit the affected HTML Plus Recent Posts by Category widgets, adding HTML paragraph tags where needed to restore the paragraphs.

If have a lot of affected widgets and/or sites, want a quick fix, and don’t mind losing the HTML-editing features added with version 2.x, you can roll back to version 1.3.2 by downloading it on the Advanced Page, unzipping it, and uploading the following files to your /wp-content/plugins/html-plus-recent-posts-by-category-widget folder, replacing the existing files:

• readme.txt
• html-plus-rec-posts-by-cat.php

Version 2.x of the HTML Plus Recent Posts by Category Widget no longer uses a basic text field for content. It now leverages the features of the Custom HTML Widget to make entering HTML easier; however, it no longer includes the “Automatically add paragraphs” option from the 1.x version.

If your existing HTML Plus Recent Posts by Category widgets are using the “Automatically add paragraphs” feature, you have two options:

1. Don’t upgrade to version 2.x. Version 1.3.2 was just upgraded so that it is compatible with PHP 8.0, and it is compatible with WordPress 5.7, so it should be a while–possibly quite a while–before you need to upgrade.
2. Modify your existing HTML Plus Recent Posts by Category widgets so that they use HTML paragraph tags where required, then upgrade to version 2.x.

As a first test of this plugin, I inserted the code:
<strong>

It didn’t change the appearance of the post links.

Lane