Unable to move or do anything in the realm due to lag

i've been facing this problem for so long and it reached to a point in which i litteraly can't do anything in the realm due to this incredibly annoying lag. why are so many people having lag with minecraft realms!? i tried to lower the settings to the lowest and i restarted my rouster but didn't work. if this continues like this im going to cancel the sub and will absolutely never reccomend it