N/A

Also worth mentioning that pressing 'Purchase credits' does nothing.

Railway doesn't support most prepaid cards to prevent potential misuse, this doesn't apply to all prepaid cards though - some might work and some may not. Although you can basically just narrow it down to: Railway doesn't support prepaid cards

However, since you're using yours on a credit based based plan, I'm not really sure why it wouldn't work 🤔

I'll go ask about that

I see. It was just surprising, as I wanted to downgrade my Pro plan (that is being paid by that same card which got declined)

You wouldn't have been able to since prepaid cards only worked on credit based plans and credit based plans were only available on the hobby plan

This should be fixed now