Thanks for the post.
Have you tried contacting Onn 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://onntvsupport.com/#product_support-2 or at 1-844-334-2355.
Please keep us posted.
Thanks,
Danny