Learndash purchases not enrolling

Payments are being processed through EDD without an issue but for the past week or so its failed to enrol customers in the Learndash course theyve purchased.

The only thing I’m seeing that looks unusual is that the “is this a learndash course” checkbox is no longer appearing on the download post (although i can select courses from the dropdown) see screenshot https://imgur.com/a/biD4brR

Any advice would be appreciated