I would refer to your CSP Partner or reseller for further troubleshooting and debug.
Proactively, I have posted below a link for the most useful resources
Useful resources for Shopify connector for Microsoft Dynamics 365 Business Central.
Product Help
The functionality in the default version of Business Central is described on the Docs.microsoft.com site. In the Shopify section, you find descriptions of processes such as synchronizing products and orders, and conceptual information about mapping of various entities.
Also have a look at FAQ or collection of walkthroughs (how-to).
Microsoft Partner
Your Microsoft partner is a valuable resource.
If you don’t have one yet, you can easily search for consulting services offerings for solutions based on Dynamics 365 Business Central and Shopify that are available near you.
You can also use Contact a Microsoft partner form.
Business Central communities
On the Business Central Community site, you have access to the Business Central Forum. You can use this forum to submit a question and learn from other Business Central community members. MVPs, partners, and Microsoft employees participate in the conversations.
Suggest new features and capabilities
On the Dynamics 365 Ideas site, you can provide suggestions for new feature and capabilities. Your input goes directly to Business Central's engineering backlog for investigation and prioritization.
Make sure that you search through the list of submitted suggestions. Chances are that someone already submitted something similar, and that entry might have already received votes. Vote if an idea already has been submitted to get it prioritized on the engineering backlog.
Where to file bugs and issues (for partners)
If you are Microsoft partner, you can submit support request on behalf of your Business Central online customers. Start at the Business Central administration center where you can easily submit a support request in the Power Platform admin center.
To submit support requests on behalf of your customer, you must be a delegated admin on the customer tenant. Your company must also have the Advanced or Premier support plan.
Engage with us on GitHub (for developers)
GitHub brings together communities of developers and other contributors to discover, share, and build software. You can find the source code for Shopify Connector in the Microsoft AL application add-ons repository. You can grab the code and contribute to the Shopify Connector.
