After days of trying without any answers on the internet and not finding anything on any forum, I finally found the solution for myself. What had happened was that removing the plugin somehow changed all the permissions of my files that were inside the folders to 755, and the correct one is 644.
I managed to solve the problem:
1st There was a file that was created in the wp-content > uploads > .htaccess folder that talked about the webp express plugin, I deleted it.
2nd After the plugin was deleted through the wordpress panel, there was still the webp express plugin folder in that plugin directory, within wp-content, I deleted it too.
Even so, my images didn’t come back, they were giving a 404 error and they weren’t showing them.
3rd I saw that the permissions of the folders and files within the folders were 755. Then I changed all the files to 644, which is correct.
And with that, my website returned to displaying the images perfectly as if by magic.
Thanks God.
