I bought a logitech keyboard + mouse recently(I don't remember the model, and I left it at home), and it worked just fine after conecting the usb dongle which came with it (it has just one for both devices), but then sometimes I lose the keyboard or the mouse signal (not both at the same time), I was wondering if it's normal for this to happen with devices which share the same dongle, or it may be some factory error so I go and change it for another one.
I know it's not a gamer keyboard nor mouse, but this usually happen when playing games, and sometimes I get some delay while writing text with the keyboard.