A client loads the server world after the seed and then slowly loads maybe 20 blocks around the player which isn't so smart because sometimes it doesn't load fast enough so if the player goes into a wall because it doesn't loaded there was a wall the player loses health which makes it not so fun to play multiplayer. Its on every device as i know.
Sry for my bad English
Servers are run by third party software and have no affiliation with Mojang. Any issues you find with servers should be reported to the developers of the server software, not Mojang.