You're on the right track with configuring URL filtering, but if the whitelisted URLs are still being blocked or showing “protocol not supported,” it could be due to formatting issues, like missing https://, incorrect subdomains, or needing wildcards (e.g., *.example.com).
I recommend reviewing how the URLs are structured in your allowlist and making sure they match exactly how the browser requests them.
Also, this detailed guide might help clarify best practices for website whitelisting and blocklisting:
👉 Website Whitelisting: Why and How to Do It