Create one Excel sheet per selected value in a loop

Dear Communtiy can you help me,

I have a workflow:

Nominal Row Filter Widget → Group Loop Start → Excel Writer → Variable Loop End

The goal is to create one Excel sheet per selected portfolio.

The sheet name is driven by a flow variable (portfolio name).

My issue is:

- If I use "append", old sheets from previous executions remain in the Excel file.

- If I use "overwrite", only the last selected portfolio is written and I get only one sheet.

For example:

- Select 1 portfolio → 1 sheet (OK)

- Select 2 portfolios → only the second portfolio sheet is present in the output file

How can I generate an Excel file containing only the currently selected portfolios, with one sheet per portfolio, and without keeping sheets from previous executions?

Thanks!