Board Thread:Bug Reports/@comment-107.167.109.165-20171122192750/@comment-27219153-20180120230131

''Barangolo wrote: ...is it possible that very slow processing power can lead to lag that does not allow for "clean" spawning of entities, therefore it multiplies them until the lag subsides? It may be the reason why this does not happen to more players, as most have machines that can cope with the lag sufficiently.''

That is the most probable hypothesis to this issue that I've heard thus far. Here is another thread on the matter, although not the first thread.