[regression/8.0.0-preview.5.8529] - Grid Columns Not Resizing Correctly (WinUI/MacCatalyst)

[TiberiusDRAIG]

Description

Grid column resizing is not behaving as expected in .NET8 Preview 5 - I'm finding that things spanning multiple columns can get pushed off the screen at certain sizes, then seem to slide back into view:

weirdGrid.webm

This doesn't seem to be view-dependent - in our actual app (the above is a simpler repro) we're having the issue using a DockLayout as the multi-column spanning layout.

Steps to Reproduce

1. Create default MAUI template app
2. Update MainPage.xaml to:

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="MauiApp1.MainPage">

    <Grid ColumnDefinitions="3*,*"
          RowDefinitions="*,Auto">
        <VerticalStackLayout
            Spacing="25"
            Padding="30,0"
            VerticalOptions="Center"
            Grid.Column="0"
            Grid.Row="0">

            <Image
                Source="dotnet_bot.png"
                SemanticProperties.Description="Cute dot net bot waving hi to you!"
                HeightRequest="200"
                HorizontalOptions="Center" />

            <Label
                Text="Hello, World!"
                SemanticProperties.HeadingLevel="Level1"
                FontSize="32"
                HorizontalOptions="Center" />

            <Label
                Text="Welcome to .NET Multi-platform App UI"
                SemanticProperties.HeadingLevel="Level2"
                SemanticProperties.Description="Welcome to dot net Multi platform App U I"
                FontSize="18"
                HorizontalOptions="Center" />

            <Button
                x:Name="CounterBtn"
                Text="Click me"
                SemanticProperties.Hint="Counts the number of times you click"
                Clicked="OnCounterClicked"
                HorizontalOptions="Center" />

        </VerticalStackLayout>
        <HorizontalStackLayout Grid.Row="1"
                               Grid.Column="0"
                               Grid.ColumnSpan="2"
                               HeightRequest="80"
                               HorizontalOptions="End"
                               Padding="10"
                               Background="Red">
            <Button/>
            <Button/>
            <Button/>
            <Button/>
        </HorizontalStackLayout>
    </Grid>

</ContentPage>

3. Resize window horizontally and observe weird clipping.

Link to public reproduction project repository

https://github.com/TiberiusDRAIG/MauiGridResizeBug

Version with bug

8.0.0-preview.5.8529

Last version that worked well

7.0.86

Affected platforms

I was not able test on other platforms

Affected platform versions

net8.0-windows10.0.19041.0

Did you find any workaround?

No workarounds other than completely redesigning views.

Relevant log output

No response

[TiberiusDRAIG]

Reproduced on Catalyst:

catalystRepro.mov

[PureWeen]

Duplicate of #15793