(If I use Firefox or Chrome on the Macintosh or if I use a Windows computer with Firefox, Chrome or IE, the same LTI link will connect to the ScoreCenter.)
Yes, we have contacted support at BrightSpace by D2L and are working with them on this issue. In the meantime, you can have your students use Firefox or Chrome on the Macintosh.(If you happen to work with other learning management systems as well, using a Macintosh with Safari DOES work with SoftChalk Cloud LTI links.)