I have the same issue as Martin did from Mar 6 '18 at 15:07 on this list. No working answer was provided for him. His link: [Unwanted macOS connection requests Also, adelejjeh asked on Oct 8 '16 at 15:36 MacBook keeps getting bluetooth pair requests from unauthorized device, and in that case the suggestion was to turn off the Handoff feature, which did not work for adelejjeh.
I had a Bluetooth connection request popup on my iMac running Mojave 10.14. It was from a device called "Nokia 7.1", which I DO NOT have! I was a bit stunned, and now I don't recall if I clicked Cancel or if the dialog went away by itself after some time. I noticed that I did have Bluetooth On on my iMac, so I turned it off (I have wired keyboard and mouse). An iPad and Google Pixel phone are my only other devices, which I rarely connect. I have no Nokia 7.1! Wouldn't this mean that either: 1) Someone is very nearby, trying to connect? Or, 2) It is some Malware trying to make me think it is my own device? Is this a Mac security hole that is being exploited? I really wonder what happens if someone clicks the Connect button! My Webroot SecureAnywhere software does not see a problem. It is definitely not "just a bug", as Martin asked if it could be. It's hard to imagine Apple has not addressed this issue that has been noticed since at least Oct '16.
I wonder if Arnold's issue Unauthorised Bluetooth device keeps connecting to Mac is essentially the same, but maybe he had clicked the Connect button in his past, and so now (May 18 '15 at 2:18) he was actually seeing the unauthorized connections (and data transfers) happening via his Bluetooth monitoring apps. In his case, the problem occurred when he had either Safari or Chrome browsers up (not Firefox). And, he turned off Handoff and did a factory reset of the Bluetooth environment. He never wrote back to say whether that all worked. In my case, I almost exclusively use Firefox, and occasionally use Safari when some videos don't work on my Firefox. It seems like all "Answers" I've seen are Not really solutions. I shouldn't have to turn Handoff Off, or Bluetooth Off, or not use Safari, or whatever. These are not solutions!