Date format not working? (or bug?)

Not sure if it’s me or if there’s a bug here.

I have a table that contains date columns. I want the dates to be displayed in the brief US format mm/dd/yy with two-digit values for month, day and year. In the builder, I open the table, click on a date column to edit it, go to Format tab and select the format I want, save, update page — and nothing changes. Have tried it repeatedly. What am I doing wrong? Or do these date format options simply not work?

Here’s a screen capture video: