Glenn K. Beaton, the sage of Aspen, explains how the Hunter Biden plea deal fell apart. It apparently was torpedoed by the prosecution's claim that an investigation of Hunter was not ended by the plea deal and was still ongoing. Beaton claims the prosecutors only said this to give them a pretext not to testify about the matter before Congress.
Meanwhile Biden's lawyers claimed that no, the plea agreement said that by pleading guilty to the agreed misdemeanors and gun law referral, he was thus immunized from further prosecution. Translation: the investigation had ended, and thus David Weiss, the U.S. Attorney for Delaware might have to testify before Congress.
The judge then refused to accept the plea deal, which she characterized as "odd" and took it under advisement for four weeks. She apparently indicated that she couldn't let the defendant sign something he believed protected him from further proceedings when the document guaranteed nothing of the sort.