Netflix will freeze with a black screen on FLEX box

Recently, my Flex box is having problems with the Netflix app. All the other apps work fine, but after a few days I need to restart (unplug) the flex box in order for Netflix to work. It has worked fine for a few years and this is a new problem. When choosing the Netflix menu item I will see "entering a third party app", but instead of the Netflix logo appearing, the screen will be black. I can exit, choose any other app and it will work, but once this occurs the only way to view Netflix is to restart the box. Something has broken with the Flex and Netflix. I really do not want to unplug this box every few days. thank you