When you say “all the suggestions” we don’t know what you’ve tried. Please run through the steps here and update your post with detailed responses as to what you’ve tried. When a staff member gets here they’ll be able to review and move forward, rather than asking you to do the same things and then having to wait for you to respond.
If it does turn out to be a black cable issue, they seem to be back-ordered currently, so hopefully it turns out to be something else!