Why do antivirus programs sometimes block random clean domains?

I’ve seen people complain that totally normal sites (even small tools or landing pages) get flagged as phishing or unsafe by some antivirus tools.

I’m curious, what causes this? Too many redirects? Bad neighbors on shared hosting?

Any experts here know what triggers this kind of false flag?

Yeah, I’ve noticed that too. Sometimes it seems like even clean sites get flagged for no clear reason. I’ve heard things like too many redirects, sketchy sites on the same server, or missing SSL can trigger it. Would love to hear from someone who really knows what’s going on behind the scenes.