Fixed in Origin 2018.

Prior to Origin 2018,if using find in Project (F3) and using wildcards in search, items in graph legends were not found. For example:

1. Create a new workbook and fill XY columns with row numbers.
2. Set col(B)'s Comment to "test".
3. Select col(B) and plot a line graph.
4. Press F3 to open Find dialog, clear all check boxes except the Text Objects on Graphs box.
5. Input " te " as Find What and click Find button.
   --> Graph Legend is found.
6. Check Allow Wildcards, input " te* " as Find What and click Find button.
   ==> Graph Legend is not found.