mobs dissapearing + error in server logs

on our server some horses just suddenly vanisht without any possible way of them escaping or dying, in the server logs i found errors like this on the exact times of them dissapearing:

[19:36:58] [Server thread/WARN]: Wrong location! (13, -15) should be (13, -10), abp['Horse'/4392012, l='Skynet', x=219,06, y=69,00, z=-232,78]
[19:36:58] [Server thread/WARN]: Wrong location! (13, -15) should be (13, -10), abp['Horse'/4392013, l='Skynet', x=219,99, y=69,00, z=-236,24]
[19:36:58]
[19:36:58]
[Server thread/WARN]: Fetching addPacket for removed entity

it doesnt seem to happen with horses only, it is happen at random with every type of mobs but as we have alot of those we never realy noticed