Ok, I've sorted the issue out. Or at least it was sorted but I was running the wrong copy handler prorgram.
When I installed my windows, the default copy handler would copy but not hide after copying, so I installed teracopy.
Also, the settings/network/etc menus would open minimised. I then ran a sfc scannow, so that was sorted. I didn't check to see if the original copy handler was fixed too.
So teracopy was slow (765mb/s) write, but after uninstalling it, the default one writes at (3.2gb/s) & closes when completed. It seems the original sfc scannow sorted that issue out.
So yes I'm glad it's all sorted now.
Thank you for the suggestions all!
MB: Asus Z690 Maximus hero
RAM: 2x32gb g.skill Trident Z 5600mhz ddr5
NVME: 2x Samsung nmve 1tb 980 pro
HYPERCARD: 2x Crucial P3 4TB nvme
CPU: i9-13900k
GPU: Gigabyte 3080 Ti Eagle OC
COOLER: Gigabyte waterforce 360
CASE: CM TD500 mesh
PSU: Corsair HX1000