The instances about mastodon has never been really keep connect to each other.
Because of each domain controller have their own opinion based on where they are, this could be because of their physical location or their mindset and vision.

Mastodon.social blocked pawoo.net( located in JP, the biggest mastodon instance) media function.

This is just one of examples,

If you ask me why this is happening? Because we are human being, it's OK have different opinions sometime.

The bright side is every boat is going to the same direction. We keep connected one way or another.