SpeedGrader conversion issue `.docx` files containing Excel graphs with fit equations

[nbeaver]

Summary:

SpeedGrader conversion issue for Excel graphs in .docx files causing certain text annotations to be lost.

Steps to reproduce:

1. Copy an Excel graph with a fit equation and R² value into a .docx file.
2. Upload to Canvas.
3. Open the document in SpeedGrader.
4. Navigate to the graph.

Example .docx file to reproduce: example_lab_report_with_excel_linear_fit.docx

Expected behavior:

Fit equation and R² value are retained.

Actual behavior:

Fit equation and R² value are missing.

Additional notes:

This does not occur for PDF files, so one workaround is to restrict uploads to exclude .docx files.

Example file to reproduce this issue is attached below.

example_lab_report_with_excel_linear_fit.docx

This bug may require the grader to manually download and inspect each .docx submission. This bug has existed at least since spring 2021 but probably well before that.