I have witnessed a sharp drop in ads earning since last week Friday (3rd March) even with an increase in web traffic.
I already know that my earnings drop on weekends (it has been the trend since I joined) but always pick up from Monday.
But this Monday (6th March) did not see any significant increase as it has always been. Rather the earning reporting was slow and when it came, the earning was still low compared to the last few month. The traffic remains fairly constant within this period and I did not apply any changes to my ads settings.