I am observing same error while I adding dataset.tablename. 

org.apache.spark.sql.catalyst.ExtendedAnalysisException: Materializing tables in custom schemas is not supported. Please remove the database qualifier from table 'streaming.dlt_read_test_files'

@Dlt.table(name="streaming.dlt_read_test_files")
def raw_data():
  return spark.readStream.format("delta").load(abfss_location)

@dlt.table(name="streaming.dlt_clean_test_files")
def filtered_data():
  return dlt.readStream("streaming.dlt_read_test_files").select(F.col("data"))

 Do we have update on this topic?