Well, from my experience, we can say that the spawning time and location is RNG according to some unknown parameters. One of the parameters maybe whether one or two spawn together. I must have found two at the same time maybe 6 times in about 12 visits. That seems to be more than a coincidence. Again, the point is that if you have long-range sensors, you'll have more chance of seeing them in your contacts panel instead of having to bump into them. It seems pretty simple to me that this must be surely the reason why some people struggle to find them and others don't.But didn’t you say a little while ago that it’s all random? If it’s random then you getting two at a time will have zero bearing on how many spawn in any other instance regardless of sensor range.
I’ve got no idea how @SteveWW57 searches for them, but I personally move around and if it’s spawned I’m probably going to “bump into it” as you put it.