Thanks for the inquiry.
Have you tried contacting JVC support yet to inquire further? I'd suggest starting there to see what options or suggestions they can provide. Each Roku TV manufacturer provides direct support for their products running the Roku OS. You can reach them here: http://www.us.jvc.com/support/ or at 1-888-582-8870.
JVC doesn't even build this model. It's a thierd party and their email support link is dead. No joy, this route. Any other suggestions?
Thanks for the post.
Customers have reported that powering down your TV and unplugging it for 5-10 minutes resolves the issue.
Please keep us posted.