On Minecraft on Mineplex what does kicked for suspicious movement mean?

It means you either lagged, or double jumped too fast in a rapid succession. A fast way to do so it to go into SG and when you sprint up stairs, hold CTRL and spam SPACE at the same time. It kicks everytime

As I'm sure you're aware Mineplex is a very large mine craft Server Network, and with that obviously comes plenty of players who attempt to hack onto the server and obtain privileges. For this reason, Mineplex have to have a very strict hack scanning system. If someone was flying, they could be kicked out of a game as this movement was suspicious, and would keep getting kicked if they continued to do so until someone reported them. This system has to be very sensitive, as some people would try to be inconspicuous about their flying, and perform it in mere parts to make sure they aren't spotted. Doing repeated or quick double jumps or sprint jumps may seem like attempts to try and fly, so Mineplex kick you just in case. Without this system Mineplex would have a lot of fly hacking players. If it is constantly happening (i.e. Every 2-3 games) then let a member of staff know. Otherwise, it's nothing to worry about.