Hi Campbell,
Thanks for reaching out.
It seems that the migration process does not convert the URLs into the staging one, there are a few URLs still showing the live URL. I would suggest you search and replace the live* URL from the staging site by using any of the free plugins available in the WordPress repository or you can go through the following article which may help you on this.
If that does not help, there might be a few different reasons for this issue, I would suggest you troubleshoot the common issues related to the Product Validation
- Location Issues
- Communication Error Messages
Hope this helps.
Thanks