The Dark Phoenix (4): The Fate of the Phoenix - S3-E14
Audio problem: When Cyclops says "Then why not trust us to deal with Jean?" his mouth is completely closed. (00:03:10)
The Dark Phoenix (4): The Fate of the Phoenix - S3-E14
Audio problem: When Lilandra is consulting the Supreme Intelligence of the Kree, his mouth movement is out of sync with his dialogue. (00:04:30)
The Dark Phoenix (4): The Fate of the Phoenix - S3-E14
Audio problem: When Lilandra's advisor is saying "The X-Men face hopeless odds," his mouth is closed for the word "face." (00:08:57)
Answer: Chris Potter, the original Gambit voice actor, did indeed quit the role in the 4th season. His last episode was The Phalanx Covenant Part 1 so it seems reasonable that Fox would limit the use of the character even though it was recast. It doesn't appear that Potter left the role due to animosity, he stated in an interview that he wished to play Gambit in the first live action X-Men film.
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