FPS drops for all players in specifics area

Hello,
today I found a big problem on my minecraft paper server. It’s a bug I’ve never seen before.
There is an area on my server where a player built his house, and everything worked fine until today. At one time, all players who were around his house began to get FPS drops (everyone had 1 FPS). There were also big TPS drops (20 to 4 TPS very quickly) when a player went to this area. I tried to restore the part of the map where there were the FPS drops, but there were not gone by doing this.
Actually, the server is running fine, but there are TPS drops only when a player go through the area.
I don’t know exactly if the bug is caused by paper, spigot, bukkit, or the vanilla minecraft server, but I found absolutely nothing which could explain FPS and TPS drops in this area. Maybe is Herobrine coming back ? :sweat_smile:
If anyone would have any suggestion, I’d would be very happy :smiley: