There is so much going on during a blood moon, tons of data being written and read about each zombie and each player, it comes down to the hardware reaching a limit and cannot keep up. 12K is the maximum world size that anyone has gotten to work with 8 players so far. Since this game is newer to you, a few versions ago we had working 16K servers running fine but the game has changed in development and that just isn't possible right now. Heck, for one alpha we had an infinite size map! Talk about never running out of places to visit.....