Problem connecting VSF with Spree

Hi! I’m trying to evaluate the potential for using VSF as a frontend to headless Spree, and I’m stuck. I’ve successfully setup a local Spree backend store with sample data that’s responding to localhost:4000. /admin works perfectly and I’ve tested the API with Postman with no problems. I’ve also setup VSF locally (localhost:3000) and the clothing store home page appears. However, VSF is not able to access the Spree database. On the VSF side the error is:

[dev:theme] ERROR No response received from Spree

On the Spree side the error is:

HTTP parse error, malformed request: #<Puma::HttpParserError: Invalid HTTP format, parsing fails. Are you trying to open an SSL connection to a non-SSL Puma?>

Does anyone know what’s going on?