why would you lose DC ESS
Sorry, I must be really crap at trying to explain things.
The original electric problem was loss of DC1 and DC2 and DC ESSential bus bar which ecam reports as DC EMER CONFIG.
You managed to recover DC ESSential by connecting it to the EMER Generator via the ESS TR. Thus, when you loose the EMER Generator, then you are back to your original condition of No DC ESSential.