Yes, if that is a 10 or 11 meter antenna there will be a loading coil at the base. But, the inductance of the coil at the tap point is essentially a short circuit to the AM broadcast band frequencies. That would be a good reason for the signal to disappear when you connect the shield.
From the YouTube video it appears that after some fiddling, the internal tuner does indeed work. And, as you demonstrated, sometimes you have to power down and back up to get it started although not usually.
It appeared as though the "wire" antenna was not stretched out rather laying on the bench somewhat coiled up. That's a problem. Extend the wire vertically as much as possible.
Also, the Talking House gets its RF ground through the ground pin of the AC adapter. If you have it plugged into a power strip that has an RFI filter, that may be part of the problem. Plug the AC adapter directly into a 3 prong wall outlet.
I use the ATU. And I get about a half mile decent signal. I tried the "wire" antenna when I first got the Talking House and found that I was doing good to get 500 feet.
Thanks for the information Mram, I'll try that tomorrow.
During night-time propagation the only free frequency 710khz has a loud signal coming over it.
(yes, I'll just run the station 12 hours not to interfere with its night-time prop)
So tomorrow during the day is the best time for me to test, I was indeed using a new power strip as well which might very well account for some of the humming.