[regression/8.0.3] Order of priority between Styles.xaml and custom css has changed in .net 8

[maestro-oc]

Description

After upgrading our project to .net 8 all of our custom css defined in a .css file and applied to a page/component is being overridden by the Style.xaml file. If the control exists in the Styles.xaml file then any css is ignored. If I remove the control type from the Styles.xaml file then the css works correctly.

Steps to Reproduce

1. Create file -> new maui project
2. Create Styles.css in /Resources/Styles
3. Add record .test{ background-color: yellow;} to Styles.css
4. Add StyleSheetExtension to MainPage.xaml
5. Add new button with basic config and StyleClass="test"
6. Run project and button will be default maui color
7. Remove the Styles.xaml from the resource dictionary in App.xaml and re run the project, button will be yellow.

Link to public reproduction project repository

No response

Version with bug

8.0.3

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

7.0.101

Affected platforms

Windows

Affected platform versions

Only tested on Windows 10

Did you find any workaround?

No no work around found

Relevant log output

No response

[PureWeen]

@StephaneDelcroix ?

[StephaneDelcroix]

works as expected for local styles and local css, have to test for global ones

[ymebrugts]

I have the same situation since upgrading to .NET8 but with Local Styles vs Global ones:
This is in the AppShell:
<Style TargetType="Button" BasedOn="{StaticResource MainButtonStyle}" />

This is set in a custom control:

var button = new Button()
{                       
      ClassId = $"{i + 1}",
      Style = (IsCircle ? Resources["unselectedCircleStyle"] : Resources["unselectedSquareStyle"]) as Style
};

Yet the one in AppShell Takes priority. If I remove the one in AppShell it works like it should.

We've added this issue to our backlog, and we will work to address it as time and resources allow. If you have any additional information or questions about this issue, please leave a comment. For additional info about issue management, please read our Triage Process.