Google core algorithm update in March 2019
Since March 12, 2019, some people in SEO related forums have found that Google's ranking has changed greatly, which should be a relatively large algorithm update.
Although Google rarely confirms that the algorithm is updated, this time it did post a confirmation on Twitter:
According to Google, this is the so-called core algorithm update, just like last August's medic update, which went online on March 12. Global online at the same time. (so to answer the question from reader ailly, it's not because they're not synchronized online. Maybe it's Japanese websites that do a better job? It is suggested to see what is special about Japanese websites.)