Excel 365 Pivot Table Slicer bug - Calibri 9 bold not right

I've noticed this issue for a while, but only just got round to doing some rigorous testing as initially I thought I was doing something wrong.

In a custom slicer style, Calibri size 9 bold appears wrong - the text spacing is weird and condensed, such that the font spacing for bold is actually less than for regular!

You can see the issue below: the Calibri 9 bold text string is more condensed:

However when I enlarge to Calibri 11 regular vs bold, the problem disappears. So it's an issue with size 9 and 10, and possibly smaller

Please let me know how to support this bug to the Excel 365 team. I attach a file with 4 pivot table custom slicer styles so you can try it out for yourself. Thanks

https://github.com/johntdata/Share/raw/refs/heads/master/Calibri%20slicer%20font%20issue.xlsx