Your products are no longer available and your Shop Store will not be discoverable on the Shop app. To activate Shopping features, make sure you meet Shop Merchant Guidelines
This is the only thing I think it could be but it makes no sense to my. If I can’t sell anything, how can I have a transaction more than 90 days old?
The error you are seeing is referring to your store being featured in the Shop app. This has no impact on customers being able to access your website or make purchases as it’s a separate platform. Shop is a shopping destination app that’s available to customers on iOS and Android. Customers can use the Shop app to track packages, browse and buy products, and engage with your brand.
To be featured in the Shop app, make sure you review and comply with the merchant requirements and product restrictions linked above. If your website is relatively new, you need to have made at least 1 sale within the last 90 days to be eligible so it’s best to simply wait the 90 days and ensure you have a sale within that time.