May I ask how does the “blocking page” look like?
Can you share a screenshot of it?
Is this happening whenever you try to access any Website which is using Cloudflare, or only on your own Websites?
May I ask have you tried using a different Web browser, or tried clearing your Web browser cache?
How about using a Private window (Incognito mode) or a VPN connection if possible?
Is it the same behaviour on your mobile phone (4G LTE, mobile data, cellular)?
Do you use any particular anti-virus software or some kind of an Web browser extension?