Kof K says the same.
COR Canada says you need to check the water it was boiled in for insects by pouring it over a shmata and checking the shmata.
The South African Beis Din doesn’t allow it.
Many Israeli hechsherim don’t allow it.
https://www.theyeshivaworld.com/coffeeroom/topic/why-is-corn-on-the-cob-not-kosher-1#post-1021292