Google makes changes to its algorithms all the time. Some are major announcements. Others are quiet, but from time to time, you may see your rankings change.
These quiet changes are referred to as “core updates.”
Google does not do this to frustrate people or ruin their search engine marketing efforts. Google does all this to improve the searching experience.
So Google continually wants us all to optimize our sites and content for mobile users, quicker download and better connection with what people are searching for at any time of day. To improve the experience of users, you need to make sure you don’t have slow page load times, irrelevant cross-links or extraneous content.
You shouldn’t chase the algorithm changes, because they will change. What you should chase are your stakeholders and make sure your site is stakeholder-centric in its content and design–not internally focused.