Extend example generates error in some cases

[petrmac]

I have unchanged version of both dgs subgraphs but I generated supergraph instead if introspecting with rover.
Apollo Gateway starts but it fails upon query with following:

GraphQLError: Validation error of type FieldUndefined: Field 'reviews' in type 'Show' is undefined @ '_entities/reviews'",
            "    at downstreamServiceError (/opt/apollo-gateway/node_modules/@apollo/gateway/dist/executeQueryPlan.js:378:12)",
            "    at /opt/apollo-gateway/node_modules/@apollo/gateway/dist/executeQueryPlan.js:261:59",
            "    at Array.map (<anonymous>)",
            "    at sendOperation (/opt/apollo-gateway/node_modules/@apollo/gateway/dist/executeQueryPlan.js:261:44)",
            "    at runMicrotasks (<anonymous>)",
            "    at processTicksAndRejections (node:internal/process/task_queues:96:5)",
            "    at async /opt/apollo-gateway/node_modules/@apollo/gateway/dist/executeQueryPlan.js:212:49",
            "    at async executeNode (/opt/apollo-gateway/node_modules/@apollo/gateway/dist/executeQueryPlan.js:132:17)",
            "    at async executeNode (/opt/apollo-gateway/node_modules/@apollo/gateway/dist/executeQueryPlan.js:120:27)",
            "    at async executeNode (/opt/apollo-gateway/node_modules/@apollo/gateway/dist/executeQueryPlan.js:103:40)"

As a result, the reviews does not get hit and does no populate the reviews subset of data.

It fails also sometimes when run in k8s even without pre-generated suprgraph (as is exaple).
Any idea what is causing that?

Thanks!