The SPP plugin has some problems with unsubscribing players when they leave the server who are currently subscribed. If one admin does /spp and subscribes then when he leaves, he should be unsubscribed from the subscribed players but when the admin logins, it auto subscribes the player again. I've set the option in the plugin config to true as well but it doesn't work.
RemoveDisconnectedPlayersFromSubscribedPlayers: true