Not converting to radios for variable subscriptions

Hi,

The plugin is not converting drop-downs to radios on the product archive page for variable subscriptions.
I have 2 variable products whose variations are being converted to radios, with the help of the code snippet from here:
https://ww.wp.xz.cn/support/topic/modifications-to-use-this-plugin-in-archive-pages/

However, I also have 2 subscription products that have variations of 6 months and 12 months but these 2 variations are still displaying as drop-downs.

Can you advise on why the subscriptions are not being converted?

Thanks,
Damien