Difficulty downloading TouchGFX and DSP packages in STM32CubeIDE 'Additional Software'

I am trying to download the TouchGFX pack within STM32Cube IDE. I'm probably doing something wrong but nothing I click on seems to do anything at all.

I can see a message asking me to select a variant but I can't see a list (unless it means the bottom line: 'Application'). If I click 'Install', the window just closes and nothing happens regardless of what I select. When I tried the DSP package, I got the same result.

In case it makes any difference I am doing this for a custom STM32G474CET6 board.

What am I doing wrong?

Thanks.