When accessing a VM console, in Firefox only and not in Chrome or IE, keystrokes are duplicated even though the keyboard.typematicMinDelay parameter is set to 2000000. I know this is likely a Firefox issue, but wondering if anyone else has noticed this and found a workaround or fix. All browsers are current versions. In the past, Firefox seemed to work correctly but I had been using Chrome for the past year or so, so I don't know when the issue in Firefox may have started. I am looking at Firefox now because my Chrome doesn't want to run Flash at the moment.
We fixed a problem with repeating keys in Firefox 54, 55, 56 in ticket 1999987. We have not found a user-side workaround. This will be in future releases of the products that consume it.
From what application are you accessing the VM console (vCenter, Horizon, etc?)