Don't know if the reporting was just delayed, but I swear that I saw the adsense reporting tool at the start of the day with 1 click and zero (0) cpm and earnings. If the reporting was delayed, shouldn't all the fields be blank?

I have a few records that showed clicks but no earnings too. I'm not sure why but I think Google qualifies/validates clicks. It may be that some clicks are not valid to Google and i don't think it is because of reporting delay.

I find that sometimes there are anomalies in Adwords so maybe it might
be the case with Adsense too. Sometimes it takes a while for your
CTRs to catch up with the real number of clicks.

I wouldn't worry about it too much. Give it a day or so to sort itself out. Google is nuts, always has been

I saw the same once. I guess it is normal situation. Example, if visitor have viewed ads at 23:59 and clicked on one of them on 00:01