Logitech Tap and Rally Bar functionality question?

Apologies in advance if this has already been explained covered or answered, but I have a functionality question with using the Logitech Tap + Rally Bar in appliance mode with our Microsoft Teams solution.

We recently purchased a Rally Bar plus a Tap for test usage. We have it hooked up like this [diagram](https://imgur.com/a/xSTCv7d). Note that in this setup, there is no PC/NUC, just a straight connection from Tap to Rally Bar, to TV. The Rally bar has been automatically updated to the latest version.

The problem is that once through the initial config, the Tap becomes... useless, for lack of a better word. Once we arrive at the actual usage screen, the Tap displays nothing but the purple background with the Logi symbol. If does not display any control, or act as a touchsreen input. The TV displays all the functional buttons of the MS Teams Room control and you either need mouse\keyboard connected to the Rally Bar, or the Rally Bar's remote to work the Teams interface.

The question is this: **Is the above the expected behavior?** In other words, is a Tap functionally useless without a PC being attached?

We have also tried attaching a different Tap, and arrived at the same results. Unfortunately we do not have a separate Rally Bar to test with. We did eventually try connecting a Teams Room PC to the whole setup, matching the more traditional deployment. In that setup, the Tap correctly: it displayed the Teams interface and users can use the touchscreen to easily interface with Teams. There are diagrams (such as the one above) and marketing verbiage that suggest the Android OS in the Rally Bar is supposed to be able to take advantage of the Tap, without a middle PC, but I can find no hard documentation or web troubleshooting that directly addresses this assumption we've made.