gigaherz

I found this while looking for solutions for the spam. I know it's old by now, but: When reading the description, I noticed you mention "/tp @e <UUID>" – this will teleport ALL ENTITIES to that uuid, not just you! @p is the one that references the player.

I don't know if this will be of use, but I used mcedit to make a copy of the save where only the affected area remains. I modified the spawn point and the player position to be close to the area where I have the issue.

Here is the link to the save: https://dl.dropboxusercontent.com/u/743491/Bug-Guardians.7z

I encountered a similar problem. I created a new Single-player, Survival game on 1.8.1. I walked to a nice beach-y area, where I built my base and did all the playing. After a while, I started hearing strange noises which I couldn't identify (I hadn't been near Guardians yet). When I walked to the ocean the other day, I saw some guardians close to the surface. Because I couldn't see any monument around, I used "open to lan" in order to enable cheats, and flew there in creative mode, using a night vision potion to watch the water properly, and indeed there is no monument where I am standing, only a huge number of guardian mobs that immediately respawn if I use a /kill command.

The seed is 4354401103591561127. Coords are 301,74,-271. The save was created already on 1.8.1 and hasn't gone through any upgrade.

EDIT: I recreated the world in creative mode and teleported to the provided coords, and I can confirm that I do not see any monument, nor Guardians, in the area.