My AS account and my S*d* account both show a marked low value of CTR for Mar 3. The website/domains in the two accounts are in totally different niches, geographies.
AS is at 87% of the average of the last 32 days.
S*d* is at 60% of the average of the last 32 days and by FAR the lowest figure for that period.
Traffic for both accounts is normal.