Since i havent figured out complete spawn mechanic for mushrooms i explain how i think it is:

Mushrooms spawn within 100m from player to dead trees, sakhal can have areas where mushroom spawn has been disabled because of too many dead trees so getting them is not too easy. And if there is more than 1 player within 100m of the mushroom's spawn location, then mushrooms spawn faster to that spot. What is little confusing is that number of player on the server greatly affect the spawn speed of mushrooms, on empty server you get mushrooms fast, and on full server the spawning almost stops or significantly slows down.. but even on full server you can get mushrooms pretty quickly if you are 2 players nearby, alone its nearly impossible to make them spawn when server is full.

Now i believe i found a bug, it has happened me twice that all of a sudden on full server mushrooms spawn really fast, even faster than they would normally spawn with 2 players next to eachothers, i had even 3 mushrooms on 1 tree. Second time this occured yesterday i was on a hill with dense forest, i spent 40 minutes going from tree to tree looking if there is a player, not to kill him but to see if this is actual bug or if there is really 1-2 other players in the area. After 40 minutes of not finding anyone, i walked 150m away, logged off and instantly logged back in, then walked 150m back to the area and mushrooms had stopped spawning completely. So its very unlikely that if there even after 40 minutes of searching was another player, that he would have left the area at the same time as i did the relog thing.

Now it doesnt sound like very serious bug, but what if it can happen with all loot, not just mushrooms, and what if its far worse than it looks like, maybe it could cause server desynch, lag on the server, other bugs, connection issues for all players on the server etc. It seemed to me that game counted me as 3-4 players instead of 1 player when determining how fast mushrooms should spawn near me.