I just bought a Brand New Surface Pro 9 i7 16GB 256GB right from Microsoft.
Ive owned it for a week, no matter what settings I tweak, or files deleted, and defender anti virus, its ridiculously slow & laggy
I wanted this tablet to replace a 5 year old iPad.
The iPad runs faster with zero lag. Its just a better piece of hardware, that costs $400 is 5yrs old. Compared to Microsofts $1,200 surface pro 9 i7, that is a week old.
Non of the recommendations listed above has done anything to fix the Slow performance, and touch screen Lag response, on a brand new Surface Pro 9 i7 16GB.