Relation with property path channels in entity was not found

[michaelbromley]

Describe the bug
Getting Relation with property path channels in entity was not found error when attempting to access OrderLine.featuredAsset via GraphQL APIs

To Reproduce
Steps to reproduce the behavior:

1. Create a new channel
2. Add a product to that channel
3. In the storefront API execute the following query:

   mutation {
   addItemToOrder(productVariantId: 1, quantity: 1) {
   ... on Order {
     id
     code
     createdAt
     total
     totalQuantity
     lines {
       featuredAsset {
         id
       }
     }
   }

4. See error:

   {
   "errors": [
   {
     "message": "Relation with property path channels in entity was not found.",
     "locations": [
       {
         "line": 5,
         "column": 9
       }
     ],
     "path": [
       "addItemToOrder",
       "lines",
       2,
       "featuredAsset"
     ]
   }
   

Expected behavior
Should not error

Environment (please complete the following information):

• @vendure/core version: 1.0.0-beta.2
• Nodejs version: 14.x
• Database (mysql/postgres etc): any

Additional context
Note that repeating the failing mutation a second time works.