Custom fulfilment service provider not being applied to a product

Shopify Partner
2 0 0

Hi All.

We update our inventory daily with price, stock levels and add new or delete no longer available product.

We have circa 5000 products, so this is a heavy lift that we have optimised by handling inventory match outside of Shopify so as to only upload the deltas.

We started with Custom Fulfilment last week and can't get it to work.

We started to populate the "Variant Fulfilment Field" with a selection of 10 providers - each product has only 1 possible provider, as part of this update process.

Sadly, despite a product identifying the correct custom fulfilment provider, the fulfilment order is not sent out (email).

The system has randomly created new providers, under identical names, but identified IN THE ORDER an app alongside those identified as "custom service Providers".

So our orders are going nowhere.

Anyone experience this or can pinpoint the simple tweak that is needed to make this functionality work?

You help much appreciated in advance.