Sorting algorithm question

I have been using Lemmy for a while now and decided to "branch out" from Lemmy.world to another instance. I used lasim to migrate all of my subscriptions over to the new account on Discuss.online. What I was expecting is to have the default view which is Everything, sorted by Hot, be somewhat similar between instances, but it is completely different. Can someone explain this? Does every instance build its own statistics that are used for the "Hot" and "Active" sort?