ShopifyProductNotAvailable Error with channable API

[HB2023]

Hello,

we are using shopify and the channable API to synchronize our orders from the marketplace Amazon. We are able to import the orders into channable, however when channable tries to forward them into our shopify we get the following error:

ShopifyProductNotAvailable(message='One or more products of the order are not available for sales at the moment[...]method='POST', status=400[...]"errors":{"variant_id":"expected String to be a id"[...]

Our shopify store is not accessible without permission yet, but normal shop orders are working correctly. 

Channable says they can only use ID for the sync and with SKUs it would not work (we are using custom SKUs on Amazon and not the shopify IDs). But should the API then not already fail importing the orders from Amazon?

To me it seems more like an issue with shopify, any ideas?