This summary is not the rule. The rule text controls.
When a case has more than one defendant being tried at the same time, the jury doesn't have to decide on everyone at once. If the jury reaches a decision about one defendant but is still stuck on another, they can announce the verdict for the one they agreed on right away. They don't have to wait until they've made up their minds about everyone.
If the jury simply can't agree on a verdict for one or more of the defendants, that's okay. Those defendants aren't just let go or automatically found guilty. Instead, the case against them can be tried again later in front of a new jury.
This rule matters because it means one confused or deadlocked juror decision doesn't hold up justice for everyone else involved in the case. Each defendant's outcome can move forward on its own timeline, even when they were all tried together.