Undefined request (404 error) on Divi when using WebP <picture> tag method

[markonikolic985]

Describe the bug
When using Divi theme and activate WebP display using tag method, there is failed request in console (https://example.com/undefined), also visible in GTMetrix like this:

And in console it looks like this:

The problem is related to Divi's custom.unified.js file, line 80. When unminified, this function looks like this:

t("#logo").length &&
                            ((q = t("#logo").attr("src")),
                            (Q = function () {
                                var e,
                                    n,
                                    r,
                                    i = t("#logo"),
                                    o = "svg" === i.attr("src").substr(-3, 3);
                                t("body").append(t("<div />", { id: "et-define-logo-wrap", style: "position: fixed; bottom: 0; opacity: 0;" })),
                                    (e = t("#et-define-logo-wrap")),
                                    o && e.addClass("svg-logo"),
                                    e.html(i.clone().css({ display: "block" }).removeAttr("id")),
                                    (n = e.find("img").width()),
                                    (r = e.find("img").height()),
                                    i.attr({ "data-actual-width": n, "data-actual-height": r }),
                                    e.remove(),
                                    A(!0);
                            }),
                            (($ = new Image()).onLoad = Q),
                            ($.onload = Q),
                            ($.src = q)),

And it looks like a problem in this part ($.src = q).

If this function is completely removed, the issue is gone. I guess Imagify fetch this dynamically when nothing is defined yet, so the error occurs.

Steps to reproduce the behavior:

1. Activate Divi theme (or make sure it is active)

2. Activate WebP display option ( tag method) in Imagify settings

3. Visit the site (front-end) and check Console output or test website in GTMetrix

[paaljoachim]

Hi

We turned on webP in Imagify and noticed a while later that an undefined error showed up when we tested in gtmetrix.
We noticed it affected the SEO at https://coinno.no over the last few weeks. Coinno also uses Divi.

I cloned the live site to a dev site and again turning off plugins and noticed that it was Imagify that caused the problem. I also assumed that it was webP that was causing the 404 error.

I have had to turn off webP to remove the error. Hopefully this error can be fixed soon!
Thank you!