I write a couple of libraries for creating GOV.UK services and Google has flagged one of them as dangerous. I've appealed the decision several times but it's like screaming into a void.
https://govuk-components.netlify.app/
I use Google Workspace for my company email, so that's the only way for me to get in contact with a human, but they refuse to go off script and won't help me contact the actual department responsible in any way.
It's now on a proper domain, https://govuk-components.x-govuk.org/ - but other than moving, there's still not much anyone can do if they're incorrectly targeted.
Google is not the only one marking subdomains under netlify.app dangerous. For a good reason though, there's a lot of garbage hosted there. Netlify also doesn't do a good enough job of taking down garbage.