Git Bash not using the source value specified in windows terminal settings

Until yesterday my settings.json for Windows Terminal has this profile for Git Bash:

...,
"defaultProfile": "{my_guid}",
"profiles": 
{
    "defaults": {},
    "list": 
    [
        {
            "guid": "{my_guid}",
            "hidden": false,
            "name": "Git Bash",
            "source": "Git"
        },
        ...
    ]
}
...

which simply worked, I could use the profile and had it set as default.

Today this profile isn’t recognized, Windows Terminal opens with a warning for unfound default profile and the Git Bash profile isn’t in the dropdown list.

I know I can just set the profile to use the path to the Git Bash executable, but I want to know what has changed.

Why did the profile using the source attribute worked before? Why doesn’t it work anymore? Where is the piece of documentation or the release note that specifies this?