Select transformation output schema is empty after renaming columns

Question

I've followed the example from the link:

https://learn.microsoft.com/en-us/azure/data-factory/tutorial-data-flow-dynamic-columns

It's exactly what I need for my project, but unfortunately, no matter what I do, the output schema of the select transformation remains empty.

Data Preview of the select transformation (and all subsequent transformations) shows that columns are, in fact, renamed as expected.

I could map drifted columns, but that transformation maps only renamed columns, and the rest I'd need to manually map which is not ideal when dealing with a lot of non-drifted columns, but ideally, I shouldn't even need to do this.

Is there a reason why this happens, and what would be the solution (preferably not a hack-y one :D)?