Wireless Display Resolution issue

We have 120 Surface Pro 9 devices at our school. When connecting Surface Pro 9 using Wireless display no matter what receiver we use (Microsoft, HD or 4k, Actiontec, EZCast) it does not display 16:9 image. It appears as 4:3. While the Surface Pro 7 and 7+ on the same receiver and connected display does. We suspect it is a driver issue.