Thing with this one, given where this system is relative to the "starting" system and it's range, it's unsurprising that it got found so quickly tbh. It's what, ~31 LY from the "starting system" iirc (since I did this at 5am with a screaming baby, my memory is a bit shot)?
Volume of a sphere is cubic (V=4/3πr^3) which means when that radius is reduced even just a little, your volume goes down dramatically. So, if we were saying there was ~5,000 systems to start with, at a radius of ~ 30LY that becomes just 500 systems to search. Throw on that, tbh, at a range of 31LY (and it's a fairly uninterrupted direction), someone could have very easily just lucked out and hit it.
As it was though, it took what, three hours to discover? If a coordinated group (such as Canonn) comprising several hundred players had a list of all systems within range of the starting system... assuming just 20 of them happened to be online (which is a very lowball figure), that's just 25 systems per person to scan (cherry picking the surface landables) if you brute forced it. It's not a big body of work.