Pre-requisites for viewing across instances

Dear Support,

I have a question about viewing communities across federated instances.

I had a lemmy.world login, but while it was less available last week, I created this lemm.ee account.

I used the very cool https://github.com/wescode/lemmy_migrate project to copy my subscriptions over, and in the end, got just a few of these:

Failed to resolve community 400 Client Error: Bad Request for url: https://lemm.ee/api/v3/resolve_object?q=https%3A%2F%2 Flemmy.world%2Fc%2F<COMMUNITY>&auth=<TOKEN>

Sure enough trying to browse to those lemmy.world communities from lemm.ee, they would show no posts.

However, if I switched back to lemmy.world and tried to view those same few communities, I would see posts.

In case there was any doubt about the instances being federated, I was able to see many other lemmy.world communities from lemm.ee, just not these few.

With just one exception, those communities posts are all visible now.

This occurred on July 3rd, before issues like this were reported: https://github.com/LemmyNet/lemmy/issues/3515

These communities were not particularly active, so assumed it was a feature and not a bug.

So is there some other perquisite to view posts from federated instances' communities? Subscriber count, post count, etc ...?

Thanks for reading.