Tunnel dies when connecting to external API

Dear community,

we’re currently trying to connect to the AWS S3 API to upload a file via multipart. We’re using the “@aws-sdk/client-s3” package and so far we’re able to initialize the upload, upload the different parts, but when we try to complete the multipart upload the tunnel dies with:

INFO    11:54:26.911  be0512ac40647bc9  status 2: 
/tunnel/node_modules/@forge/runtime/out/sandbox-isolate/api/index.js:59
                callback.applySync(undefined);
                         ^

Error [CredentialsProviderError]: Cannot load config from environment variables with getter: (env) => (0, util_config_provider_1.booleanSelector)(env, exports.ENV_USE_DUALSTACK_ENDPOINT, util_config_provider_1.SelectorType.ENV)
    at resolver.js:42764:15
    at resolver.js:44192:28
    at async coalesceProvider (resolver.js:44252:24)
    at async Object.useDualstackEndpoint (resolver.js:44264:28)
    at async getEndpointFromRegion (resolver.js:29561:34)
    at async serializeAws_restXmlCompleteMultipartUploadCommand (resolver.js:8609:68)
    at async resolver.js:40423:21
    at async resolver.js:38468:22
    at (<isolated-vm boundary>)
    at /tunnel/node_modules/@forge/runtime/out/sandbox-isolate/api/index.js:59:26

Does anyone know why this happens and how this can be avoided? Many thanks in advance!

Best regards,

Johnny