did a simple test, they marked collectibles, nothing more (marked 30). nothing was triggered, including 2-3 people trying to mark the same collectible. have 3 other tests involving collectibles i will try, see if i can trigger the bug.
this was from a guildy, cannot verify its authenticity:
[15:48] Delusion: I have seen that happen twice, it is a bug when you get a visitor that comes from an adventure direct to your island. It was a storehouse that was "stopped"
More of the same "new" content with a different bow? I will give more of the "same" towards my gem accumulation.
OK, I was on adventure, guildie said "mark my eggs" I went there directly because I was waiting for general to transfer. I noticed a storehouse was "glowing" and asked what kind of buff works on a store house ? He said it had a 24hr stopped but no icon saying what kind of buff it was.
I just had this happen to one of my fishermen while a friend was marking collectables on my island. Stopping and restarting the building has no effect.