Has anyone else seen a huge wave of bot signups on Substack this week?

We've gotten thousands over the last couple days. They seem to be coming through the Recommendations feature (they all show one specific publication as the source).

Several other creators have told me they're seeing the same thing.

The emails are all from a small pool of throwaway domains, so it looks coordinated, not random. We don't really know what's going on beyond that.

I'm proud of my 80,000+ real subscribers, and obviously concerned about how this could impact deliverability & domain authority.

But I'm getting (the usual) crickets from Substack support. Has anyone actually gotten them to respond to something like this? It's clearly a platform-level issue.

Substack - would love a reply