@dwadia “Cmd error” is right up there with the “Failed to disable Echo” error messages.
I would drop the 115200 baud rate right down to 9600 for the “Shield” connection method.
115200 is fine for “Standalone” but not shield.
Do you know what baud rate your ESP is set at in the firmware (not in the sketch)? You can find out by sending AT commands to the ESP.
Take a look at this cmd error thread Repeatedly receiving "Cmd error" even with simplest examples
For that Blynker it was a bad router and his system worked fine at a friends house.
I think you might have tried with the Pi as an AP but you could also try your Smartphone AP to see if it helps.
You can also search for all the other “cmd error” threads to see if any of them help.
Please keep us updated with your progress.