Lemmy has a huge problem with federation of small servers it seems? At least my server has immense troubles loading anything from some servers and it seems clicking the ! Links forces the server to load them.
I think every instance should promote a random community every day to prevent this tech-only and only big community monopoly
You need to use a hardened browser with as little unique identifiers as possible. Then you need to delete cookies and use different or unified IP addresses, obviously.