Different checkbox tick displayed while editing then the one actually printed or displayed in print preview

[bogdanmaris]

Affected versions

• 81.0a1 (2020-08-18)

Affected platforms

• Windows 10 64bit
• macOS 10.15
• Ubuntu 18.04 64bit

Steps to reproduce
pdfjs.renderInteractiveForms - true

1. Launch Firefox
2. Access a PDF form with fillable content (eg: https://www.irs.gov/pub/irs-pdf/f1040.pdf)
3. Tick some checkboxes
4. Enter print preview
5. Print as pdf

Expected result

• User is displayed with the same design of the checkbox tick during editing and after print or in print preview.

Actual result

• Checkmarks are ticked with X but saved with ✓ for this particular pdf

Additional notes

• S4 as suggested severity, not a severe issue in my opinion.