To reproduce:
1.) Open Thunar.
2.) Select the "View" menu from the menu bar.
3.) Select "View as Detailed List".
4.) Select the "Edit" menu from the menu bar.
5.) Select "Preferences".
6.) Go to the "Display" tab.
7.) Select "Icon View" under "View new folders using:"

You can open any folder or close and reopen Thunar it will always list
items in "View as Detailed List" mode and ignore the setting set
in preferences.