In the current setup exclusively offer 1-year plans, with renewal turned on. Is this the reason why we are experiencing the bug?
Because the "renewal" has been created in stripe rather than in CB?
I'm not sure what you mean by renewal being turned on. Do you mean auto recurring payments? You can't have auto recurring payments with an offline payment.
If you mean the upgrade is auto recurring at Stripe then it can take up to 24hrs to verify the payment in which case being pending is normal. You should have a Webhook from Stripe that pays the basket so you need to be sure you've properly configured Webhooks at Stripe.