ZATCA Registration Portal Error Outside KSA

I am experiencing a persistent “This site can’t be reached” error (ERR_CONNECTION_RESET or TIMEOUT) specifically at the final step of the ZATCA (Fatoora) registration process when accessing the portal from outside Saudi Arabia

Login & Navigation: Works perfectly,
Able to enter all customer and business details.,
The OTP is received and accepted.
immediately after entering the OTP to finalize registration, the browser fails to load the next page