I have not personally been effected by this, but a lot of my friends have. On tower defense, people will be kicked from the server for hacking, usually its flying or pvp hacks. it seems to be do to elytra, whenever they get it by spamming a button. they stay for a short time, then are kicked for hacks. i do not have a screenshot due to the fact it did not happen to me. We tested it by me not getting elytra and a friend getting it. She was in fact kicked and was not hacking. just making staff aware of it!