@ZorroBlaster it's not a bug, most players leave the game and come back later, some enjoy the game alone, some stay in certain PH level for a long time to gear up their performance or max their island.... I even saw a player who only attacked 10 or 12 times in their whole game which was around 230 days and was PH8, Simply gathering resources from gold mine and grog dystilery to upgrade their island
If they were in a guild before the stats were introduced. That guild is not recorded in the previous guild stat.