SKU0936 LCD Display backlight not working?

I purchased a DFR0936 LCD Display shield from Pi hut, which described it as having a backlight:

https://thepihut.com/products/i2c-rgb-backlight-16x2-lcd-display-module

I have tried all the examples that come with the library, as well as the example from the wiki here:

https://wiki.dfrobot.com/_SKU_DFR0374__SKU_DFR0936_LCD_Keypad_Shield_V2.0

All seem to work with my Arduino Uno R3, but none make the backlight light up. Do I have a faulty display shield, or am I missing a bit of code to turn the backlight on perhaps?