On some sites the bounce rate in Google Analytics was 0% for all sources. No matter which period I choose (1, 7, 30 days). Though earlier all was normal. And if you look, for example, for the data year, the performance is not equal to 0.
According to Yandex Metrics indicators at the same sites at the same time not 0-tions.
It is clear that the bounce rate is calculated in the search engines differently. But to 0 - this is weird and more like a lie.
What could be the reason?