Hi NemoResh ,
According to your description, you got errors on the SSL connection establishing stage (AT+CIPSTART). So I may suggest you debug the same stage from your PC using tools like telnet, curl, or openssl s_client.
Here is an example for validating SSL connection with openssl s_client on PC:
openssl s_client -crlf -verify_return_error -connect project-name-rtdb.firebaseio.com:443
If everything will be okay on PC, try to use WireShark to debug network failures when your ESP sends network packets. I think it can be achieved when you start a WiFi network on your notebook and setup WireShark to sniff packets on that new wlan network interface.