Hi all,
I had a similar problem and tried everything (updating drivers, etc.). My surface pro 7 screen works in UEFI mode, so I think it's a software issue on my end. Every time I'd use the surface, the touch screen would stop working at a certain point, both with touch and pen. Only restarting the surface would get them working again. I'm using a surface slim pen. I finally noticed that when I'd uninstall the "Surface Pen Cfu Over Ble LC Connection" driver, the pen and touch screen would work better. I've finally rolled back this driver, and things seem to be working better.