a bit curious tonight while staring at it (the equation) on my computer screen, although Einstein-Hilbert action changes in form in the dimensional reduction, the equation of motion stays invariant in form except it picks up the energy-momentum tensor that is, EH action is not conformally invariant but the equation of motion is although there is the presence of a source, the energy-momentum tensor! in the reduced (1+1) dimension
https://foxtrotpaparomeo.wordpress.com/category/general-relativity/general-relativity-general-relativity/