Hi. I still have this (jpg.webp is resized in HTML or CSS from 1200×800 to 569×320. Serving a scaled image could save 38.3KiB (81% reduction) showing in GT Metrix even after I have added in layout/blog/single/posts the correct image size.
1. Media Attachment Size – this allows you choose the actual image to be loaded
2. Set the Width and Height – this allows you to change the size of the image being displayed. Which is handy if you have an want to align the image to one side and other styles.
If you want to load the exact image then choose the correct Media Attachment Size and leave the Width and Height empty.
This article explains how to add new Media Attachment sizes for your choosing:
We changed the Image Resizer in the latest version of GP Premium as for a very small group of users it created problems with their servers.
The new version which only enables itself on new sites works differently.
We now recommend you create a specific image size following this article, select that and DO NOT add the width and the height values.