Having a closer look at the differences before and after the algo update, no changes in two of them and the new one (3 month's old) the traffic keeps climbing. What I found curious is that in all of them the organic traffic sent by Google has a much lower bounce rate.
The new site went from 73.91% to 10.73% and yesterday 3.89%, and the other sites which kept the same traffic numbers also saw improvements on the bounce rate (39% to 16%, and 88.24% to 63.64%).
Can you check and confirm whether you're seeing similar results?