GAME ZIP 64 - LED matrix not working. Is it broken?

I know there’s an issue with the GAME ZIP 64’s LEDs in MicroPython at the moment, but mine isn’t working with MakeCode either.

I created a test program to display a rainbow on the whole display, but only the first nine LEDs will light:

Even the pre-built Snake game from https://www.kitronik.co.uk/5626-game-zip-64-for-the-bbc-microbit.html fails.

Interestingly though, if I use the beta version of MicroPython, I can use the whole display.

Anyone have any thoughts? Have I got a broken GAME ZIP?