Game Mechanics: Sister of Spire fell through island 7 on flat ground

[bigsykedaddy]

We were fightin Sister of the Spire on island 7 like we always do and out of no where she fell through the island and started summoning ppl to their deaths. We were fighting her on completely flat ground where we fought the one before her and she just poofed under island and started summoning at around /loc -961 , -443. Eunomia helped out like always ( thanks )