Entity shows differently in I-phone companion App

This is bizarre and for ages did not realise /and so kept altering stuff!

I have created a template entity by adding 2 entity values together. I get the result I want.

When looking on a history graph it shows the result, changing with time. No shocks

Everywhere except the I-phone companion app this entity shows as null, but it shows as a figure in the app. But it still shows in the history?!

This gets really weird when I put this into a Sankey chart( great integration) as this only shows the section for this entity when on the I-phone companion app!

The entity has a unit (Wh), is call sensor.grid_to_house
Is this a reserved name or something?

I’ve checked using ingress, duckdns,direct Ip, every browser I have installed and even on my I-phone it vanishes when using a browser.

Any ideas?

This sounds like HA is having all the right values, but a conversion on the iPhone companion app is faulty and resulting in a wrong output.
It is most likely therefore a frontend issue with the dynamic rendering of the card.

It ONLY shows on the app, and fails to render in the entity card in browsers, I just get ‘null’, or I would agree with you.

The mystery deepens, here s screen shot showing browser results
the entity card shows the figure
the history chart shows the figure
the history card shows ‘null’
the figure does not show anywhere else (eg the sankey card)

and now both are ‘null’