Unable to sign in to ChatGPT account using Apple Intelligence on my MacBook Pro

Thank you for your information.

I was able to sign in with disabling firewall filter. (ESET)

I tried disabling the firewall on the ESET app once, but it didn't work.

However, it worked after disabling the filter in [System Settings] - [Network] on Mac.

Thank you!

I was having the exact same issue here but on MacOS. It turned out that disabling Warp (kind of Cloudflare VPN) did the trick. If you have any VPN enabled, try disabling and give it a go. If you don't have VPN, sometimes it might be a DNS filtering or anything which is blocking these network calls.