Azure Data Factory - External Call gets lost after successful publishing, results in broken data flow

Question

Hello,
I am using Azure Data Factory to build an ETL pipeline. I use an 'External Call' transformation to get data from a list of URIs.
After successfully publishing the data flow, the 'External Call' transformation gets disconnected from upstream transformations - the box can be found 'very far' from the rest of the boxes, as per the attached image.
This bug keeps happening and it is impossible to run any pipeline that uses this data flow, because it gets broken instantly.

The first attached image demonstrates the successful publishing of the data flow. It also shows that data can be successfully pulled from the REST api, hence proving the lack of error in the code.

How can this bug be corrected? What am I doing wrong?

Thanks!