Gas Usage Up Up and Away

Had my Tado X installed for a couple of weeks now. It’s installed properly, works as it should regarding calling for heat etc. only thing I have on schedule is the hot water control, 2 hours in the morning and 2 evening.

Since changing across from Nest and considering the fact that I can now control heat calls for specific rads rather than heat the whole house unnecessarily, all I have seen (according to Ovtopus) is my gas consumption climb and climb on a daily basis. Clearly something is wrong, surely I should be seeing the opposite and gas usage going down as I now only heat the rads actually needed?

Any thoughts?