https://journals.ametsoc.org/view/journals/clim/34/21/JCLI-D-20-1013.1.pdf
...and why does that matter? You literally explained it yourself. That's like Trump claiming there is no global warming because it snowed at the White House.
"The impact of ENSO on GMTOA is asymmetric about lag 0 (Fig. 5), meaning that the energy content of the Earth system is maximum near the peak of El Niño events, a result that has been confirmed in observations (Johnson and Birnbaum 2017). Peak energy input into the Earth system is 0.13 Wm^-2 per standard deviation 7 months before Niño-3.4 maxima and the peak energy loss is 0.21 Wm^-2 per standard deviation 6 months after Niño-3.4 maxima"
The global mean difference is much smaller than 20 Wm^-2 (which is a cherry picked figure at a certain instant and region of the atmosphere)... And far less than the GHG which the number you gave appears to be a global mean and a 24/7 pressure on the planet. And that is only during the brief lag period after an El Nino peaks.