Thank you but I found the cause of the problem; I hadn’t noticed that the images (especially if uploaded in groups) are then automatically inserted in the AVIA image blocks as “average size” so 300px basic. Uploading one at a time at the time of uploading and positioning you can choose the desired size. Once you have added the image in AVIA, if you want to change its size you must delete the image and reinsert it so that the size choice appears. A bit cumbersome but in the end I solved it.

I have deleted the plugin