Double letters can indicate it may need cleaned. You can carefully remove the keycaps and blow/brush out any dirt or dust from the actual switches beneath the keycaps.

The pcb when manufactured has flux residue this combined with air causes the residue to corrode. I disassembled the board and found this on multiple PCBs from this particular model (both iterations) Note: the residue on 1 board was all over solder areas it looks like oil and PCB is a hint darker where residue was left. (The manufacturing process has a solvent to remove this but seems like that process was missed.) Good news is I fixed it by using lemon juice on qtip to clear the corrosion then removed the residue of the flux and lemon juice with 91% isopropyl alcohol. Put i back together and keys no longer register multiple times. https://old.reddit.com/r/LogitechG/comments/aonhdv/g910_keys_not_working_or_doubletripple_registering/

Taking off the keycaps and cleaning mine helped for a short while (about 4 weeks), then the problem came back with a vengeance. Taking it apart further to check out the PCB was problematic.

This is literally what happened to my 8 key. Exact same model and same amount of years purchased. This is wild.