Site header logo and parallax image on homepage do not display on iPhone

Do not use WebP, it works in Chrome only. If you check your website in Firefox or Edge on Windows, these images are not loaded also. When I check the source of your website in Firefox or Chrome, the image source is with JPG extension, but Firefox returns that image is missing, and if I try to open it in other programs, it says that format is not recognized. Only Chrome, Vivaldi and Opera can see these images because they all use Chromium in the browser with WebP support.

That is why iOS Safari (and most likely normal Safari on macOS) don’t see these images.

Also, I am not aware of any method to automatically replace WebP with PNG/JPG for WordPress or any other CMS.