为什么在Excel for Mac中使用VBA时，我的InputBox没有显示提示文本？

I've been building a system that will keep track of student grades, using Excel. I've coded it under Windows, where everything works fine, but when I test it on the Mac version of Excel (the latest version, 15.24, I believe), the InputBoxes only show the title and the text box for the input data; the prompt text is not shown. Here is an example of the code that I use to handle the InputBoxes: I've been building a system that will keep trac