Thank you Glenn, I deleted the "webwork-open-problem-library" directory from the templates directory of all the courses, including modelCourse. Not sure how it appeared that at first, the issue is fixed now.
WeBWorK Problems
OPL Problems Visible in Local Problems
This forum has a limit to the number of forum postings you can make in a given time period - this is currently set at 10 posting(s) in 1 day