"Reset all zones to default level", as suggested by other posts, did not help me.
Here was what I did to transmit the tax successfully:
I got my tax file in TurboTax ready to transmit - to the point where the "Transmit" button is shown, and pressing it would file the tax.
I then disconnected the power cord to my home wifi route and left it off for about 10 seconds, then reconnect it.
When my home wifi is available again, I then clicked on the "Transmit" button, and voila, I got the confirmation that the tax was filed, and later an email saying that it was received by the IRS.
