My Logitech keyboard and mouse began to act glitchy. Mouse cursur jumping all over the screen. And delayed keystrokes and some keystroke letters repeated multiple times.

The Logitech support site suggested unpairing them. Which I made the mistake of doing. Too late I realized that both keyboard and mouse were not only unpaired, but I no longer had the ability to use my desktop at all.

Calling Logitech support was maddening. However after an hour of troubleshooting, a tech suggested pairing the devices to my wife's laptop. Once we did that and she removed her laptop, they worked once again on my desktop. Pairing them on her laptop somehow enabled them to be paired to my desktop. I didn't even have to do anything. I don't know why. But all that matters is they work. And the glitchiness is gone for both.

So unpairing and repairing is the right solution. But make sure you retain access to your desktop by unpairing one Device at a time.