Start with the software side
Some boards let you raise the debounce time in their driver or web configurator. Adding even 1 to 2ms filters out most phantom double presses with zero hardware work.
Clean the offending switch
Pull the keycap and blow out dust with compressed air, then drip a tiny amount of contact cleaner into the switch stem hole and press it twenty times. Dust and oxidation are behind most single key double typing cases.
- Test the key in an online keyboard tester after each step
- If only one key fails, swap it with a neighbor to confirm the switch
- On hot swap boards like the NOVA 75 PRO, replacing one switch takes seconds
- Avoid eating crumbs over the keyboard, they jam switch leaf springs
When it really is the switch
If cleaning and swapping do not help, that switch has worn out. This is exactly why hot swap support matters: you fix the board yourself in seconds instead of replacing the whole thing.