The short answer here is No, but the longer, more correct answer is Yes. 🙂
No: AFAIK, there is no way to block an account from logging into a CB.
Yes: Add a secondary domain and only allow your primary domain to log into your CBs.
Adding a secondary domain using a subdomain of your current domain will cost you nothing but a few minutes of DNS work.
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https://wheretofind.me/@NoSubstitute