Multiple Radiators - only one heating

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So I have 4 Radiators. All with TRVs in the living room. The Temperatur is set to 20C. When it fell to 19.9C I heard the valves - so that’s fine.

15 minutes later I checked - and the radiator I am sitting next too was still cool.

And only one - the one which I use as sensor is warm.

Shouldn’t all four heat ? Or does it regulate how many radiators it needs ?