FB is requiring phone number but I'm using a proxy, how do they know?

I've been creating Facebook accounts recently with no issues. I would simply use CCleaner to clean my browser and then create a new email account and then create a new Facebook account. I would never get asked to provide a phone number to verify my account until now. Now every time I create a new FB account I'm immediately asked to add a phone number to verify my account.

So then I tried creating an account while using a VPN. That didn't work. Then I bought private proxies and tried that. That didn't work. I'm left to assume that FB is somehow recognizing my PC or browser even though I use CCleaner to clear cookies and everything else.

Is there a way to stop FB from recognizing my browser? Would it help to reinstall my browser? I really don't know how they're remembering my PC or browser.