After a support request I have been informed that Weglot is not able to detect images in order to add its url to the translation board if they content a srcset label additional to the standar src.
That labelling is made by WPRocket or Imagify plugins (And maybe much more) when enabling the webp image format. That actions make google pagespeed to set as “pass” the section “use next generation image formats” and it will be nice to be able to translate them as well.
I have the same problem, I would love if Weglot could see webp images.
Very annoying! Support blamed it on a caching issue on our end. Glad to see others having the same issue.