Will magnet affect a Bluetooth devices RF reception?”
Bluetooth RF designer accounts for magnet, effect of magnet is not much different than effect of battery. Effect of either battery or magnet is usually “ground plane”, it bends / reflects the RF signal from emanating as a spheroid to more hemispherical shaped (not totally, some signal does still go in the other direction as well). If you are using Bluetooth (USB) dongle, it is more likely that RF signal is bent or distorted at that end. I have seen at least one (Bluetooth or WiFi) dongle which came with a USB extension cord and stand to position it vertically away from computer. You may get better results with Bluetooth dongle plugged into USB hub at end of a USB extension cord.
