Freezes on realm

When playing on my Realm, I am experiencing frequent freezes (every 10 sec. on average, lasting around one second). It happens even when I am alone on the Realm. Lowering video options has no effect and I am still getting the freezes. The memory usage never goes above 60% , it does not seems to be related to it (I am freezing even at less than 10% memory usage).

However, when playing solo mode on the world i'm playing on the Realm (by downloading the latest backup), I am not experiencing any freezes or FPS drop (stays at a constant 60 FPS).