If a visitor typed your address and a few minutes later clicked through from a social post, the whole visit used to count as direct and the social channel got no credit. Now, arriving again mid-session from another external site, or through a link with different UTM tags, starts a new session under the new source. Internal navigation, reloads and returns from payment pages are unaffected.
The rule is on by default for new projects and can be switched off under Sessions & channels in website settings. Channels and Referring sites in the Sources report also gain an "every arrival" method that shows how many arrivals each source actually produced. More in How sources and channels are classified.