Well, I discovered something really weird and so bad that it gotta be a bug...
I looks like from the transition of Fusion 2.0 to 2.5 something have changed breaking any kind of page loading extension (WebView, Web Control Object, even ActiveX elements)
Some pages will break because javascript is disabled and these extensions will run in Internet Explorer 7 Compatibility View instead of using the normal IE or Edge engine.
Phi and I was discussing about this on Discord, and we found out that in Fusion 2.5 the WebView extension was loading correctly, with JS and using Edge's engine (although it thinks it's on windows 8 instead of 10, and using an older version of Edge)
But on Fusion 2.5, it's broken. He tested the older WebView version (1.30) on Fusion 2.5, but the problem persists.
I believe that some change in Fusion 2.5 broke it, because it doesn't seem to be a problem with those extensions.
It could also be the reason some people complained about WebView in the past, as seem here: Please login to see this link.
Here's the test, Fusion 2.5:
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Now Fusion 2.0:
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As you can see, something is broken.
All these pages work normally in any browser in the computer, IE, Edge, Chrome, Firefox...
Disabling firewall and antivirus does not change it.
Please, this needs to be fixed...