Button sizing broken by .NET9 when using the Mac UI Idiom

[piersdeseilligny]

Description

It seems like the sizing/layout of buttons has been broken by .NET 9 in Mac Catalyst, when using the Mac UI Idiom.

.NET 8 (correct):

.NET 9 (incorrect):

Adding padding does not fix the issue, as it ends up being inconsistent depending on the length of the text. For example, both of these buttons have Padding="0,25", but now have inconsistent padding.

Steps to Reproduce

Any buttons without an explicitly set size seem to have this issue:

        <HorizontalStackLayout VerticalOptions="Center" HorizontalOptions="End" Spacing="10" Padding="20" >
            <Button Text="Cancel" Clicked="UIAction_Cancel_Clicked"/>
            <Button Text="Save" Clicked="UIAction_Save_Clicked"/>
        </HorizontalStackLayout>

Link to public reproduction project repository

No response

Version with bug

9.0.10 SR1

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

Unknown/Other

Affected platforms

macOS

Affected platform versions

MacOS 15.1.1 (at least)

Did you find any workaround?

No response

Relevant log output

[similar-issues-ai]

We've found some similar issues:

• NET 8 :: Sizing of windows, text buttons and icon buttons are off #21285 , similarity score: 81%

If any of the above are duplicates, please consider closing this issue out and adding additional context in the original issue.

Note: You can give me feedback by 👍 or 👎 this comment.

[tj-devel709]

@piersdeseilligny Thanks for the issue, could you share how you are using the Mac Idiom with a reproduction? I am not seeing this behavior on my end. I do believe there are some known weird behavior with the mac idioms though.

[dotnet-policy-service]

Hi @piersdeseilligny. We have added the "s/needs-repro" label to this issue, which indicates that we require steps and sample code to reproduce the issue before we can take further action. Please try to create a minimal sample project/solution or code samples which reproduce the issue, ideally as a GitHub repo that we can clone. See more details about creating repros here: https://github.com/dotnet/maui/blob/main/.github/repro.md

This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.