Hive TRVs not working correctly

I’ve connected some hive TRVs to ZHA via a sonoff zigbee bridge flashed with tasmota but they aren’t working as expected.
No matter what the TRV’s actual and target temps are, they are always in heat mode, surely this isn’t normal?
When I try to manually change the mode, either nothing happens or they switch back to heat after a few seconds.

Any help is appreciated.

Have you read through the docs for the TRVs? I use Aeotec z-wave ones so YMMV, but on mine, “heat” is the mode used whenever the TRV is trying to achieve a specific target temperature, “dry” is fully on, “eco” and “off” are what you’d expect.

Bear in mind that HA only supports a very limited number of HVAC modes so sometimes integration authors have to assign labels to modes that don’t really make sense.