Dragging the fill handle in Microsoft Excel: a white gloved hand appears instead of a black cross (Mac, Mojave, Excel 16.28)

I want to "drag the fill handle" like this: https://support.office.com/en-us/article/copy-a-formula-by-dragging-the-fill-handle-in-excel-for- mac-dd928259-622b-473f-9a33-83aa1a63e218

But for some reason, when I place my cursor in the lower right corner, I often get a gloved hand cursor instead of the black cross that you would use to "drag the fill handle." This hand does not allow me to drag the fill controller. How can I prevent this hand from appearing when I try to do this?

I am using Excel 16.28 on a Mac with Mojave.