Lucy Tomas

<p>Very simple plugin that will search for all the first images of your published posts, pages or custom post types and set them as the featured image.</p>
<ul>
<li>You can choose the post type you want to run the plugin on.</li>
<li>Option to overwrite the already selected futured images.</li>
<li>Option to select From / To date.</li>
</ul>


Set All First Images As Featured

still works

It simply didn't recognize any images in any of the posts, and so didn't work. :(

Didn't see the images in the posts

IT works on 5.0.3

Sets the first image of your posts, pages or custom post types as the featured image.

codersantosh

Acme Themes

<p>Regenerate Thumbnails – Acme Fix Images is a handy WordPress plugin designed to resolve issues related to image thumbnail sizes. If you’ve recently adjusted image sizes in your Media Settings or encountered display problems due to improper thumbnail sizes, this plugin can help you ensure consistency and proper display of images across your website.</p>
<ol>
<li>Log in to your WordPress admin panel.</li>
<li>Navigate to Appearance => Acme Fix Images.</li>
<li>Select the image sizes and options you wish to fix.</li>
<li>Click “Fix All Images” to regenerate thumbnails according to your chosen sizes.</li>
</ol>


Acme Fix Images – Regenerate Thumbnails

Fix image sizes after you have changed image sizes from Media Settings. Ensure your images display consistently across your website.

Set All First Images As Featured vs Acme Fix Images – Regenerate Thumbnails