I try to run a (very simple) DLT pipeline in with a resulting materialized table is published in UC schema with a managed storage location defined (within an existing EXTERNAL LOCATION). Accoding to the documentation: 

• Publishing to schemas that specify a managed storage location is supported only in the preview channel.

So - with no surprises - running this pipeline in the current channel ends with:

com.databricks.pipelines.common.CustomException: [DLT ERROR CODE: EXECUTION_SERVICE_STARTUP_FAILURE] 
Schemas with specified storage locations are not currently supported for UC enabled pipelines.

 But when I switch to the preview channel, it does not work either, but this time the error is different:

com.databricks.pipelines.common.CustomException: [DLT ERROR CODE: EXECUTION_SERVICE_STARTUP_FAILURE] 
Schema tstexternal has a specified storage location that does not match the pipeline's root location: None

Is there a chance for it to make it working? Can I setup "the pipeline's root location" somehow?

Any help welcome.

Thx

Pawel