If you have an Android device, it would be worth trying the de facto third party UPnP controller, the BubbleUPnP app (no surprise it & BubbleUPnP Server helper software share the same developer). Have you installed its latest firmware (if any)?

It wouldn't be the first UPnP streamer to not work properly out of the box. I suspect you could be right in that there could be a problem with the Teac itself. The only other way to use a streamer with Roon is to use a device that supports the proprietary Roon Advanced Audio Transport (RAAT). Even more curiously, others have certainly managed to bridge the Squeezebox & UPnP streaming technologies, so I'm not sure why Roon can't be made to support UPnP directly. They have provided support for HQP, AirPlay and oddly the older (& now defunct) Squeezebox devices, but no other streaming technology. In any case Roon Labs have made it quite clear that they have not intention of providing support for UPnP/DLNA renderers, due to 'technical issues'. So I don't think it makes sense to add a UPnP streamer to that system, though you would think that Roon and the Teac streamer (ie without HQP) should be valid.

Not sure if it's uPnP, but I'm curious if the high-priced spread (Roon and HQP) is worth the cost in terms of Just Working & ease of setup.In the Roon and HQPlayer combo, the HQP is being used as an endpoint, ie, much like the Teac being used as a UPnP streamer is.

Upnp player os x