Formatting an image to webp is losing some of the transparency in the image

[jaandrews]

Prerequisites

• I have written a descriptive issue title
• I have verified that I am running the latest version of ImageSharp.Web
• I have verified if the problem exist in both DEBUG and RELEASE mode
• I have searched open and closed issues to ensure it has not already been reported

ImageSharp.Web version

3.1.1

Other Six Labors packages and versions

SixLabors.ImageSharp.Web.Providers.Azure : 3.1.1

Environment (Operating system, version and so on)

Windows 10

.NET version

8

Description

When the problem image is formatted to webp with "?format=webp," some of the transparency is lost.

What it should look like

What it actually looks like

I'm loading this package as a dependency of Umbraco.Cms 13.2.2, so if the below steps fail to reproduce the issue, there may be some configuration in it I'm unaware of.

Steps to Reproduce

1. Format the attached image as a webp file.

Images