[Bug] Expander header image does not change after first tap if source is AppThemeBinding

[3steve3]

Description

When setting an expander arrow image that indicates if it is collapsed/expanded, if I set a light and dark version with AppThemeBinding, the image does not update after the first tap.

Stack Trace

Link to Reproduction Sample

https://github.com/3steve3/ExpanderBug

Steps to Reproduce

1. Set image source as {AppThemeBinding Light=DownArrow.png,Dark=DownArrowDark.png} and {AppThemeBinding Light=UpArrow.png,Dark=UpArrowDark.png}.
2. The arrow will not change after the first tap.

Expected Behavior

The arrow changes back from the up arrow to the down arrow when the expander is collapsed.

Actual Behavior

The arrow stays as an up arrow.

Basic Information

• Version with issue: 1.7.3
• Last known good version:
• IDE: Visual Studio Community 17.2.4
• Platform Target Frameworks:
  • iOS: N/A
  • Android: 12
  • UWP: N/A
• Android Support Library Version: 31
• Nuget Packages:
• Affected Devices:

Workaround

Instead of using {AppThemeBinding Light=UpArrow.png,Dark=UpArrowDark.png} inside of DataTrigger image source, use <Setter Property="Rotation" Value="180" />

Reproduction imagery