In my home setup I have my work laptop in a docking station. Behind that is an old desktop PC, which is in a metal case. They are close because I don't really have the space to put them further apart.
Some months ago, I replaced a failed keyboard, with a new wireless keyboard and mouse. I plugged the dongle for the wireless keyboard and mouse, into the work laptop's docking station. However, I would experience frequent lockups of the mouse and keyboard. The laptop wasn't frozen, as I could hear videos going on (bad when in a Zoom call with colleagues), but the input devices weren't working. The only way I could fix it was by doing a power down of the laptop via the docking station's power button.
I went to Best Buy to talk with them about how to fix it. They said that it was the metal case of the old desktop which was causing the problem. That it was interfering with the signal to the dongle from the wireless keyboard and mouse. They recommended another wireless keyboard and mouse with a more secure connection between keyboard/mouse and dongle. So, I bought it. I've been using it for 3 weeks. It is an improvement. Before my work laptop would freeze the mouse and keyboard 6 to 8 times per day. Now it only does so 1 to 2 times a day. However, even that is a nuisance, and it can be a real problem if I'm doing something critical.
Here's the questions I have about my situation. First, it does seem like what the guy at Best Buy said was correct, that the signal from keyboard/mouse to dongle can be affected by the metal of the old desktop. (The old desktop is 5" away from the dongle. That's as far as I can get them apart.) Taking the distance between the two as a factor, how far should I get the old desktop from the dongle in the work laptop?
Second, is there some shielding I can use to stop the interference between the dongle and the old desktop's metal casing?