However there are still two ways to look at this: The defeatists will say that the open web of the old is now fubar, there is no point in building websites now because whatever you do you are at the whim of BigTechs to dictate the term of your website.
I try to keep more optimistic viewpoint. We can see that this is more or less the standard behavior of any antivirus measure, and your browser/antivirus service is tasked with an impossible job of deciding if the data it renders is benign or malicious, and whatever heuristic/criteria it comes up with is going to be leaky and cannot cover every edge cases. Platform should structure their system so that your components are localized, so it will be less susceptible to those kind of outage. Of the top of my mind, what step you should be taking: - Separation of domains between for your own assets/web and what the clients upload. A CDN, online bucket may help you here. - If you are doing a website builder, try to enforce the client to bring their domain to publish. Your default domain should be for evaluation purpose only.
It's hard world out there, sympathy to OP for being in this shitty position.