Season 2 episode 16 of Naruto has 2 audio tracks playing over one another, the first is english, the second sounds like japanese but it's difficult to tell.
You neglected to mention the app/service used.
Contact the app publisher/service provider about the issue.
I did say it was the Roku Channel, you just didn't read the title.
Ah, you mean The Roku Channel app.
You'll need to contact Roku directly and report the content issue:
Chat or email: https://support.roku.com/contactus (choose setup/ultra/other/need more help?)