Hello Angus. I'm Greg, here to help you with this.
How are those buttons in your screenshot out of reach? Do they not work, because that indicates Edge needs repair?
1) Try dragging the Window down from it's top, then clicking the middle Maximize button a few times to try to program it to open full screen.
2) If that doesn't work then drag all four sides to fill the screen or open where you want it and in the size you want, press the middle Maximize button a few times to program it to open there.
3) If that doesn't work then there is likely a conflict with another app. Establish a Clean Boot to get rid of Startup freeloaders that can hog resources and cause issues by conflicting:
https://www.makeuseof.com/clean-boot-windows-11/
4) Try these fixes for fixing the position and size of where a window opens:
https://www.computerhope.com/issues/ch001478.htm
https://winaero.com/how-to-resize-a-window-to-a...
https://www.raymond.cc/blog/how-to-resize-an-un...
If Edge buttons are not working properly then try these fixes for Edge:
https://answers.microsoft.com/en-us/microsofted...
Let me know if you have any questions or I can help performing any of the above steps. Based on the results you post back I will have other steps to try if necessary.
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