You are not the first one to ask this. We dont know, my guess would be, because Selfhost is so popular it federated almost everywhere, and spammers probably saw that and attacked through that.

Yup, report, block. Contact admins if possible ( or warn others in the Defense HQ Matrix channel )

I installed it now, it is working fine with my pihole. It wasnt that much of a hussle but a bit of googling.

Does it really do that? I thought if pi-hole blocks it, it just says nothing here, normally a pc then looks up your secondary dns and then ads are back at it.

This was my experience when i did that.

Nice work!