On my 8310 my fat fingers
never missed the keys. When I changed to the 9700’s and discovered my fingers were not designed to easily use the keyboard I was left with only one solution, loose weight.
Failing that I had to get used to the difference. I still make the same double key strokes and I tried some of the keys you are having issues with and exactly the same keys were typed. Not all.
This may not be your problem but just an offer on another possibility.