Content Type is not the same as Folder Format. Content Type is a specific kind of Folder Format, one that is triggered by lots of files of a particular type in the folder. (See number 1 in the Folder Formats: Detailed Guide for a rundown of the different types of folder format.)
The way to tell which format is in use is to hover over the Format Lock in the status bar. Do not click it, just hover the mouse over it. (See number 6 in the Folder Formats: Detailed Guide.)
Make sure you close the window and open a new one when testing format changes, to avoid inheriting old settings that the window was preserving. (Number 6 in the Folder Formats: Quick Guide. Numbers 7 & 8 in the Detailed Guide explain some of the reasons why windows can preserve their current settings.)