Problem: Not all symbols or levels are listed for coverage annotation layer
When invoking the Layer Properties dialog box for a coverage annotation layer, the list of unique symbol ($SYMBOL) or level ($LEVEL) values is incomplete.
The coverage annotation layer is initially scanned for unique symbols and levels, but in order to reduce the time this takes, only features in the current view extent are searched. This means that if you are zoomed in on an area smaller than the full coverage extent, features outside this area are not included.
Solution or Workaround
Make sure that the entire coverage extent is drawn at least once. Notice that ArcMap will add unique symbol and level values as you pan and zoom the map. This ensures that the symbols and levels that are visible on the map are listed.