In the featuremanager design tree expand drawing view to show the flat pattern feature.
Solidworks sheet metal drawing show bend lines.
This toggles the visibility of sketches and if it is off the bend lines sketch will be hidden the second method i used was to expand out the flat pattern in the feature tree and find the sketch bend lines2 could be other numbers shown.
You can control the precision for sheet metal bend line notes in tools options document properties tables bend.
Expand the flat pattern feature right click bend lines and select show or hide.
In the drawing view propertymanager you can.
Displaying solidworks bend lines the first method i tried was to go to view sketches.
No bend lines or bend notes are show then your bend line sketch for that view is more than likely not set to show.
Hiding the bend lines also hides the sheet metal bend notes.
Search toggling the visibility of bend lines in the solidworks knowledge base.
To unmerge bend notes right click the merged note and click unmerge bend notes.