When I open the "Format Cells" tool panel (with CMD+1) to change cell Borders, the upper left "Line Styles" window doesn't show any line styles, except 'sum" line, unless I click on the blank window. Been using this feature of Excel for many years and this is the first time that I've had this problem, until I moved to a Mac mini M2 Pro. Once I click in the blank panel, the line styles show and everything is normal.
see image
