Using the ωPBEh functional, which was shown to represent energies and wavefunctions accurately, we have studied excitedstate minima in solution highlighting the importance of planarisation and excited-state symmetry breaking leading to markedly different photophysics between the molecules despite their similar molecular structures. The adiabatic singlet-triplet gaps of Cz-AQ and Cz-BDT were found to be very similar not providing a suitable figure of merit to differentiate between the two molecules. Conversely, we have related the strong TADF activity of Cz-AQ to the existence of a strongly emissive symmetry broken S 1 minimum with CT character whereas Cz-BDT formed a dark locally excited S 1 minimum. Moreover, Cz-AQ was characterised by a dense set of states of different character connecting the T 1 and S 1 states providing a pathway between them despite their comparatively large gap.