Roku will not open streams but it used to.
Can you further describe what you mean by "they fade"?
Is this on all channels or only one or more particular ones? Which ones?
What is the full text of any error messages you receive?
And it is always a good idea to include your Roku model and model number (found via Roku menu path Settings > System > About) as sometimes the proper response to your questions may vary with Roku model.