Okay, started the investigation and the issue is 99% certain that it is the Adalo API server that is the problem. Nothing to do with Stripe or the clients card number. Stupid that the stripe component blames the users card rather than Adalos server.
I’ll put a rush on making a proper stripe component with a proper server for you, hopefully I will turn it around soon.
In the meantime, if you want to contact Adalo support and tell them that it looks like the call to
https://adalo-stripe-v2.herokuapp.com/processstripepymt is failing and if they can look through the logs, if you give them your Customer Id and Connect Account Id they should be able to investigate what is going on on their end while I build a new component that works.