I'm sorry to hear that you're experiencing picture stuttering on the YouTube App. I have carried out some checks on your TiVo® box remotely to also rule out any potential signal/power level issues and all is looking fine there.
We are currently working on this at present to fix this issue. Our fault teams are aware and will be working on a solution.
Thank you for your patience.
Tech fan? Have you read our Digital life blog yet? Check it out