The syntax style is set to change string to uppercase. When using F9 or Shift+F9 to execute a select query which has a where clause value of string in CAPS, during the first execution, no rows is returned, and upon moving the cursor to another line, and re-execute the query, result is returned. The data is in upper case.
Basically, because the capitilization is set for 'strings', the way the editor works is that even though on the screen it appears to be upper case, behind the scenes it is actually still lower case. Once the cursor is moved to a different line, then it will actually convert the lower case to uppercase permanantly (just like the screen displays).
Move the cursor up or down a line in the query. Kindly share this information on the editor's behaviour in regards to String capitialization with colleagues who are affected. Also our recommendation is as best practice to set the string to uppercase using Oracle's 'upper' function, or to actually type the string out in CAPS. Let me know whether this clarifies.
At this time, there is nothing that can be done, as this is found to be a known issue with the backend editor processor.