UFH multiple zones and zone valve question

Hi,

I have a (perhaps overegged) configuration of the following:

• 5 x TRVs on upstairs radiators
• 4 x TRVs on downstairs radiators
• 3 x seperate UFH zones controlled by manifold, each with a smart thermostat
• 1 more smart thermostat (intending to use this to control 'general' house temperature as per traditional thermostat)

First of all, hot water and the radiators are working A-OK after a jumper switch (thanks Tado support).

However, next to the boiler/tank in the garage are the 3 x zone valves - hot water, radiators and UFH.

The radiator one opens fine all good, hot water great.

The UFH one either isn't wired or correctly or isn't opening. But reading through the documentation I am wondering if this needs to be controlled at all by Tado? Point A, All Tado docs I have seen reference controlling a zone valve on a single zone by physically wiring to the thermostat, Point B, surely the manifold is controlling the flow ultimately so worst case the pipe between boiler and manifold gets warm.

I think the UFH is calling for heat correctly it's just the zone valve not opening. But is it actually correct I should lock the zone valve open (unless we need to do maintenance or whatever) and let the smart thermostats control the manifold?

And then relax and walk about barefoot?

( Follow up question, how can I configure a 'general' house temperature via smart thermostat #4)