On servers almost everything is the Minecraft default character "Steve" and it lags out my game plus it's mainly on "The Hive" and "Galaxite"

So I play the online servers such as "The Hive" and "Lifeboat" and almost everything turns into the Minecraft default character known as "Steve" after around 2 minuets. I have tried everything I can think of and this has happened for a few updates now. Is it my Xbox or something with my Minecraft? Thank you for the help.     Sincerely Isabelle.