Tuya TRV not pairing

I’ve purchased some of these to connect to my HA running on a Pi 4 with Sky Connect.

https://www.aliexpress.com/item/1005006239016783.html

I can’t get them to pair with either ZHA or Z2M. I have some Sonoff buttons that pair fine with either both ZHA and Z2M. I’ve moved the Pi and Sky Connect dongle in case of interference from my router. The Sky Connect is connected to USB 2.0 with an extension lead and there’s no SSD attached so I don’t think interference is a problem. Plus the Sonoff buttons work fine and it is also picking up my neighbours Philips bulb.

I put the TRV in pairing mode as the manual says and can see the pairing light flashing etc

Has anybody had similar trouble with these or products like them? What could I try next?

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Update, these won’t pair with a non Tuya bridge. Had to return them to the manufacturer and replaced then with Sonoff TRZB which worked straight away.