Max allowed pop-up size

I noticed that the max size a pop-up is allowed to be is tied to the size of the browser window where that pop-up is launched from.

Opening a pop-up from a 1920px wide window can at most be about 1520px wide. This is causing me issues because a site I frequently use needs its pop-up to be at least 1600px wide to display all information.

Changing nothing except the size of the browser window to 3840px wide I can open pop-ups up to 3000px wide.

I want to completely sever this connection between the window size and the largest allowed pop-up. How do I do that?

Win 10 latest build.