about 6 months ago, I ordered new mechanical keyboards for my wife and I. After a day or two, her keyboard would randomly, intermittently spam the 6 key. I tried replacing the '6' key switch to no avail. I never had a problem with my keyboard so I gave it to my wife, same make, and model as hers. Didn't fix the problem. A couple of months ago I completely rebuilt her computer, everything is new, case, motherboard, cpu, gpu, hard drive, everything. She tried the mechanical keyboard again, and again the computer would intermittently begin spamming the '6' key. She's now on a 3rd keyboard with the same issue.
3 keyboards, 2 computers, completely fresh install of windows at time the computer was rebuilt. I'm running out of ideas. I suppose the mechanical keyboard could have corrupted the windows keyboard driver when she plugged it in? Any ideas what could be causing this?
*Edit: Restarting the PC fixes the problem temporarily. Sometimes this only happens once per day, some days it takes 5 + restarts throughout the day.