Stripe connect issue (400 error)

Hi i have set up a stripe account and set its test API in hive press as instructed in the guide.

I’m set up in test mode. I set up a test (fake) express account for the one vendor. I then purchased a listing using the stripe test numbers and then marked it as complete in the buyers dashboard.

However when i go into the stripe dashboard and click on the connected accounts. It doesnt say anything about payments but show an error with the same date and time i marked the work as complete. I’m really confused, any guidance would be really appreciated.

Also does stripe connect know automatically how much commission you take from each vendor (because mine are all on an individual basis) or do i need to somehow set this up in the stripe account manually?