Wires rule, wireless drools

So for about fifteen years this has been my TV/movie watching sitch — I’m over here, and the computer that plays the stuff is over there *points at bookcase*. And I control this with this handy li’l keyboard. Now, when I first started this thing, I went through about half a dozen keyboards until I found this one. Most mini keyboards have a pitiful range — like a metre at most. But this one (which is not Bluetooth, but uses a USB dongle) works pretty well. That is, normally it has, like, a 98% success rate. Which would be infuriatingly low for a normal keyboard, but since I’m just using this as a “remote” — i.e., to stop/start movies and control the volume etc — it’s not that bad. But! On random days, it drops to 70% or so. It does not seem to be correlated to anything I can find — not the battery charge, and not… well, that’s all I can think should affect this, because I’m stationary and the dongle is stationary. A neighbour blasting a microwave for hours on end? Or a wifi AP gone…