I would like to know just how you uploaded webp images with jpg extension
We don’t actually do that anywhere in our site.
As David mention, the link you’ve provided is not built by us.
Did you check the link David provided?
https://www.webnots.com/how-to-serve-webp-images-in-siteground/
If that doesn’t work, then please check with SiteGround’s support team.
My plugin suggestion is another solution.
This is not a theme related question so we can’t really help with much more.
Thanks for your understanding.