So I went to file today and was receiving this error when I tried to use my credit card to pay for state filing "Unable to sign you into TurboTax Cloud. Please check your sign-in info and try again."
The kicker is that it has to be security related because I changed my PC's DNS addresses to 1.1.1.1 and 8.8.8.8 and everything worked fine. Submitted perfectly, both Federal and State. Only after getting super frustrated did I find a support thread mentioning something similar.
I've the same issue since last Saturday and have spent 5 hours on the phone with three agents with no resolutions.
I tried modified my IPv4 DNS to the settings you mentioned, 1.1.1.1 and 8.8.8.8 but I still failed to file both my federal and state (NJ) returns.
Help!
Unfortunately, all we can suggest in the community is to call TurboTax Customer service. Here is a link: Turbo Tax Customer Service
I was able to through this problem by creating a new rule in Windows Defender Firewall.
Selected New Rule under inbound rules
Selected Program: %ProgramFiles%\TurboTax\Individual 2024\64bit\TurboTax.exe
Selected Allow the connection if it is secure
Took defaults for the rest and then it worked for me.