I see. Thank you for the further explanation.
This actually means the issue is a hardware issue on the keyboard itself. Think of your keyboard as a maze of tiny pathways (tracks) on a circuit board. When you press a key, it's like sending a signal through that specific pathway. If there's a crack in the pathway, the signal might not get through unless you take a different route (pressing another key at the same time sends it through a different track) or sometimes you can use more force (pressing harder). Adjusting keyboard settings won't fix the broken pathway unfortunately
Things that can cause this type of cracks on the tracks include: debris build up over time, heat, liquid damage, or simply age, over time, the circuit board can become brittle and more susceptible to cracking.
You can further confirm this by using an external keyboard via USB or bluetooth, it should work fine via a different keyboard.