I didn't think bleed worked either and have spent ~10 hours just trying to get it to work. Finally I had a breakthrough.
Make the document size exactly how you want it after it has been trimmed. Then apply the bleed measurement that your printer needs.
Then create a background box that extends beyond the document to the (document+bleed total measurement).
Not try exporting with your PDF Export>PDF>More>Include Bleed
I was in the habit of creating my document, bigger than it needed to be, then setting an internal/negative bleed. Maybe some printers need it done like this and that's why I got used to doing that way. Who cares, solved now!!
Hope this helps those of you frustrated by AD Bleeds