Spent a few hours debugging this today with Stripe support on speed dial and we couldn’t find the solution (the screens show it’s working):
Testing locally, using my demo project and keys was fine.
This shows me signing up to a fake “starbucks” subscription in my test Stripe account:
But have added in some error handling today for edge cases and this should fix it for you (and any others with this issue) 
Checkout Stack 1.0.6
- Plans and products have been working; just improved error handling to fix in some cases where it wasn’t working for subscriptions
Please download it now from within RW - emails gone out also
This should help with your keys you send through