PowerServer is correct and PB is wrong. Also, PB uses table_columnname when creating the dw via the IDE, so PB is only wrong with syntaxfromsql.
this is my submission to appeon on this subject:
https://www.appeon.com/standardsupport/search/view?id=3860
it should always return table_columnname - if you have 2 tables with the same column name then you have no clue which table it is linked to without the prefix. it needs to be consistent for every column it creates. Even with only 1 table in use it would be easier if it consistent and always used table_columnname.
The way it is now makes it difficult to know when to use just the column name and when to use both regardless of PS vs PB.
What i do is to check if a column exists via describe - i use tablename_columnanme. if it exists, then i know to use the prefix and if it doesn't i don't....