Inhumans Saga: Part 3: Beware the Hidden Land - S2-E4
Continuity mistake: When Thing pulls Johnny away from Crystal, Johnny's left glove comes off in Crystal's hand. Moments later after the Fantastic Four have escaped from the Great Refuge, Johnny's left hand is gloved again. (00:19:58 - 00:20:20)
Six Forgotten Warriors Chapter 4: The Six Fight Again - S5-E5
Other mistake: The news footage of the elderly Six American Heroes being attacked by the Insidious Six is merely clips from the previous episode.