I can only assume it is due to fact we share one votifier for all servers.
we use vanilla votifier it allows us to send votes across all our servers so does not matter what server you play you will get rewards for voting regardless.
We are not making servers just to boost one server, all our servers are legit vanilla servers. I assume some one is reporting us for using same votifier as that is only reason i can see votes be disabled.
id prefer not to use two votifier for each server i like to minimize resources on my server so this version of votifer works the best for us and many others who use it.