I am still quite new to Lemmy, but think I understood the basics. I noticed something strange though. I first created an account at a different instance, where I subscribed to a number of feeds. As that instance was temporarily overloaded one day I created a new account here, and subscribed to the same feeds. Now that the other instance is working normally again I decided to compare the two accounts in order to decide where to stay for good and I noticed that with the same settings, (Show all subscribed feeds ordered by Hot for example), it looks very different. The feed on the other account shows more current posts than the one here. If federation is working, shouldn‘t both accounts show me a more or less identical feed?
I think I read there’s currently a bug with Hot (and maybe active too?) sorting that can crop up when an instance is not rebooted for a while. Most people were suggesting to use the other sorting options till it get fixed, with a lot preferring “Top Day” or “New Comments”.
I tried to find the discussion or the github issue back but I had no luck, if I find it I’ll add an edit later, so until then take what I wrote with a pinch of salt.
EDIT: I think this is the bug report: issue#3076 and it seems someone is currently working on a fix!