In short.....

There was an algo the facilitated the "trending" feature on primal.

One user figured out how to hack it and "trend" specific users.

Primal blocked those users and a few others involved in the exploit.

The users involved have large followings so when they complained, things got really noisy on thousands of feeds across all clients.

I think there's been some changes to the Algo and transparency since.

But basically, the only folks that were impacted were primal users that followed the users that were blocked. I think there was 5 of them. But with large followings.