I had a similar issue happen at the beginning of October. I posted a request for help here but received no responses. I was still able to access my project from the console, but they said they found that a file that had been uploaded to storage was being used for phishing. Anytime someone opened a file from my storage, they got a big red screen saying that they had reached a dangerous website. Super frustrating. My security rules protected any files from being accessed without permission, so I couldn't figure it out. I put in an appeal once a week for a little over a month and I just received about 5 emails on Tuesday "sincerely apologizing for any inconvenience" and saying that they had found nothing wrong with my files and removed the warnings.
I guess keep putting in the appeals and hope they get to it soon. I have to think they're using AI to scan all of the files and stuff and that's what's causing the false positives. This experience has caused me to start looking elsewhere for cloud hosting.