Actually, there's an abundance of information about instancing and scanning. Long story short, no, I don't think it's working properly in Open/PG, and it is actually working in solo correctly, but in Open/PG the effects of instancing and event registration cause what should be happening to solve the puzzle to essentially "break".
Look at what we do know. You can stack multiple (for arguments sake, 20) "scanning" missions to the one location (try out the PRE surface base in Pleiades to see this in action), scan one of the multiple data beacons that will spawn there (twenty of them, one for each mission you take), and it'll register completion for *all* twenty missions, and you get a success message for each mission. The one you scan disables, meanwhile the other 19 are still active. Scan another one, you get another 20 completion messages for each mission again.
Now lets look at what's being observed. Things like:
- People in wings who aren't doing anything get a data entry when a wingmate successfully finds a scan combination (Scanning event registers for all wingmates)
- Everyone sees an active beacon. One person scans it, it deactivates... meanwhile other players still see the beacon as active (Scanning the beacon only disables it for one person)
Now assume that you've got 8 obelisks, 4 active, 4 inactive. To get the other 4 to activate (like what gets observed in open with different obelisks to those mapped after people randomly scan/approach things).
So lets say you have to scan Beacon 1 with Item 1 in your hold, Beacon 2 with item 2, 3 with 3 and 4 with 4. If you get any one of these wrong, you've broken your chance to activate others. In solo, that's what, a possible 256 permutations if ordering mattered? That's a significant space to try and solve to get 1,1 - 2,2 - 3,3 - 4,4
But get four wingmen, one with item 1, one with item 2, one with item 3, and 1 with item four. Each of you scan all four obelisks and bam, because of the way the event registration seems to occur under the hood based on previous observations, you've brute-forced the entire problem space (Because Obelisk 1 registers as having been scanned with item 1, 2, 3 and 4 thanks to the event registering for all wingmates when you scan, same with 2, 3 and 4. In all that, 1 got scanned with 1, 2 with 2, 3 with 3 etc etc).
Now that example only used 4 obelisks and 4 items. The initial state of the puzzle is, just considering obelisks and items, 21 (or 26) permutations of items in the hold and 15 active obelisks. That's 6.8122319e+19 possible combinations if order of events matters. Far less if order doesn't, but still a significant amount.
Personally, that's what I think is going on under the hood. There's certain events you need to trigger with certain things in certain ways, but because those conditions can "stack" in open or groups, you start to see things unlocking far easier.
Yeah, my instinct is that it is multiplay breaking the quest by giving unintended progress, not solo failing by shutting players out. But we'll see.