Can you try your phone in Safe Mode @OnePunchJohn ? Using Safe Mode on a Samsung phone or tablet allows you to force the device to run the essential operating system, and disable most 3rd party applications. It's designed as a diagnostic tool to help solve issues with connectivity, battery life, apps, and more. To do this press and hold the Power button until you see Power Off, Restart and Emergency. Press and hold the Power Off icon until it shows a Shield, tap the Shield and the device will restart in Safe Mode. Once done, monitor the device for two hours to see if the issue persists.
Have you checked this with the YouTube app developers to see if there is something wrong with the app that they will need to sort on the next update @Robbie-35 ?