Font issue with matrix in rdl file

The fact that the expanded levels fall back to Courier New is the giveaway - Courier New is the default substitute the Excel rendering extension uses when it can't apply the font you specified on those rows. So the font is being lost on the dynamically-expanded child rows, not genuinely set to Courier New.

A few things that usually fix it:

- Set the Font on the textbox (cell) itself for every level, ideally as an expression based on the row-group level, so each level gets its font explicitly rather than inheriting from a parent group that collapses on expand. Setting it per textbox stops the fallback.

- Make sure the font (Algerian, and whatever you want on the lower levels) is a TrueType font installed on the rendering host - the Power BI service / report server machine, not just your authoring PC. If the font isn't present server-side, the export substitutes Courier New, which is exactly the symptom here.

- Sanity check: render to PDF. If PDF shows the correct fonts but Excel doesn't, it confirms it's the Excel rendering extension's handling of toggled rows, and the explicit per-textbox/per-level font is the workaround.

So: apply the font explicitly at the textbox level for each row-group level, and confirm the font is installed on the server doing the rendering.