My realms lagging

Hi ! Is like 2 months i buy a realms pack to play with my friend but recently my realms is very laggy. When i destroy block they come back, when me and my friend try to fly with elytres they are so glitched they won't open or didn't start flying. i lost so many firework. I don't understand before we never get some lag but now is insane .. The piston and redstone never working good. The noteblock are very laggy. Please can we have some explain?