You can always flag the issue with MGo and they may re-load the scanlators upload, or if it’s a recent chapter they may even delete it and await a new upload request from the scans team. I do find it odd though, that it’s always webtoons and the first section that is affected. If you happen to find that it results from differing comics but the same scan team, you should get in contact with them directly or leave a comment on the comic page. But as I said before, flag it when you see it to MGo, there is a flag symbol on the left of the screen in reader view, select report issue and add your comment.
How do you fix blurry chapters