I've tried a few communities between lemmy and kbin this way.

When i'm logged into lemmy(or not) and view some kbin community it shows me there is either scarce community activity or none at all. While if i visit the original community on kbin it shows a lot more.

The example with the pc gaming community works well. lemmy shows the last new post was 13 days ago. and kbin shows multiple posts made only 3 hours ago.

Another example: Stargate through lemmy shows 0 posts while kbin has low activity but does have posts 3 weeks ago.

Can somebody confirm this? Is this a bug?