Realm monster animation lag

Hi, in our current Minecraft realm, we started seeing a ton of monster behaviour lag (i.e. skeletons, creepers, all hostile mobs move in a laggy manner and aggro really slowly). This started happening as we're working on a project approx ~20,000 blocks away from spawn and are pretty heavily using command blocks. If so, is there any way to reload the server (without sacrificing any progress) or otherwise fix the realm's inherent lag? It doesn't affect players but only monster behaviour.