HSSF vs XSSF and accounting number format

More of a curiosity than a call for help.
We are using POI and Scott Klement's HSSFR4 to generate excel workbooks from RPG.
Recently decided to implement XSSF instead of HSSF.
We had setup a CellStyle using the Accounting format without the currency symbol.

TempStr = new_String('_(* #,##0_);_(* (#,##0);_(* "-"_);_(@_)');
NumFmt = SSDataFormat_getFormat(DataFmt: TempStr);
SSCellStyle_setDataFormat(Accounting0: NumFmt);

In .XLS and HSSF the format would show 12345 as "12,345". - perfect.

When we changed from HSSF and .xls to XSSF and .xlsx 12345 shows up as "$ 12,345". - Not perfect.
Excel shows the formatting as: "'_($* #,##0_);_($* (#,##0);_($* "-"_);_(@_)" (Note the "$")

I had to change the formatting to this:
TempStr = new_String('#,##0_);(#,##0)');
NumFmt = SSDataFormat_getFormat(DataFmt: TempStr);
SSCellStyle_setDataFormat(Accounting0: NumFmt);

Now Excel sees the cell as formatted as a number: "'#,##0_);(#,##0)"

Paul
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