I have a test that opens a new window when the button is clicked but the window is not maximized. I switched to the current window and use the await t.maximizeWindow() but the target window still not maximized.
At the moment, support for multiple browser windows is a beta feature and has several limitations. So, you cannot resize child windows or take screenshots or videos of them. You can find more information in the TestCafe documentation: https://devexpress.github.io/testcafe/documentation/guides/advanced-guides/multiple-browser-windows.html