Issue: (one-sentence summary)
Asked support to downgrade Metal → Black which worked fine.
Now I’m unable to pay for Black plan, “payment failed”. There’s no attempts shown at the card issuer.
Tried two cards which both works fine as underlying cards for the day to day transactions.
There’s also no charge amount displayed anywhere during the process.
Nice way for Curve to loose customers as it’s not possible to subscribe 
How to reproduce it:
Tap Pay now on Your Black plan.
OS:
iOS
App version:
3.71.0 (33776)