If the thrust isn't right around 65% coming down the last 500 feet then something is not right barring extreme wind or different flap settings than normal. Hint #1.

Hint #2 is the lack of noise and buffeting there would be.

That said, if they had three green then Embraer has some work to do.

I expect this to be an aircraft problem.

Nice that jetBlue claimed to have seen that the gear was not down but didn't do anything about it. Hopefully they meant they had seen it all after the sparks because I don't think anyone would see no wheels and not speak up.