Some iframes do not display correctly

[baggins]

Hi,

In my installation I have a Denon AVR which has a web interface to control it. I wanted to include this feature in my visualisation uing an iframe, but while trying to do this I came upon some strange behaviour with different browsers.

On Linux when using Firefox, Chrome, Opera, only one half of the page is loaded (screenshot 1).
On Linux when using Qupzilla, rekonq, the page is loaded correctly (screenshot 2).
On Windows using Edge only one half of the page is loaded.
On Windows 10 using Safari the page is loaded correctly.
On IOS using Safari the page is loaded correctly.

The half that is displayed is actually the bottom half but it stays on the top of the page.

On Linux with the browsers that show the page correctly, on the other hand I cannot display the data in the trendlogs. The graph is displayed, but clicking on 'Data' does not do anything. Also the individual data points do not light up in the graph. With the browsers that do not display the page correctly I can see the data in the trendlogs...

I have already changed the User Agent but this made no difference.

[admin]

Try opening dev tools (F12) and check the error console. It looks like some JavaScript is not working in the iframe.

[baggins]

Try opening dev tools (F12) and check the error console. It looks like some JavaScript is not working in the iframe.

Since this seemed to be browser related, I made a simple html page with an iframe in it to show the AVR page.
Screenshots of the console are attached. There is an error related to some permission denied.
Why would it be denied permission in one browser and not in another?

BR