Azure Data Factory Dataflow - Window Transformation Column Pattern Issue

Question

I'm facing an issue, when I add a column pattern to make a function that affects all columns matching a particular criterion, even if the function successfully resolves and the dataflow is saved, the expression is gone when you re-enter the dataflow again.
I am doing this on a ‘Window’ type transformation - Column pattern
The expression used is:
Matching condition :
type == 'double'
Field: $$
Expression : avg($$)

This expression helps to find the type 'double' on the columns and calculate Avg salary. The same column pattern works well in derived column activity.