CI job says successful but wwwroot remains empty

I am using the following yml file:
```
name: Build and deploy ASP.NET app to Azure Web App

on:
push:
branches:
- master
workflow_dispatch:

jobs:
build-and-deploy:
runs-on: windows-latest

steps:
# Checkout the repository
- uses: actions/checkout@v4

# Install Visual Studio Build Tools with Web development components
- name: 'Install Visual Studio Build Tools'
run: |
choco install visualstudio2019buildtools --package-parameters "--add Microsoft.VisualStudio.Workload.WebBuildTools --includeRecommended --includeOptional" --ignore-checksums -y
shell: powershell

# Restore NuGet packages
- name: 'Restore NuGet packages'
run: |
nuget restore "My.sln"
shell: powershell

# Build and publish the project
- name: 'Build and publish the project'
run: |
$msbuild = 'C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\MSBuild\Current\Bin\MSBuild.exe'
& $msbuild "MyProject/MyProject.csproj" `
/p:Configuration=Release `
/t:Package /p:PackageTempRootDir=..\publish
shell: powershell

# look for the publish output folder - works
- name: 'List directories to find publish output'
run: |
Get-ChildItem -Path "publish/PackageTmp" -Directory
shell: powershell

# This works as expected
- name: Upload Artifact
uses: actions/upload-artifact@v4.0.0
with:
name: published_webapp
path: './publish/PackageTmp'

# Deploy to Azure Web App using publish profile - says successful but wwwroot is empty
- name: 'Deploy to Azure Web App'
uses: azure/webapps-deploy@v3
with:
app-name: 'MySiteName'
publish-profile: ${{ secrets.AZURE_WEBAPP_PUBLISH_PROFILE }}
package: '.'
# I've also tried:
# package: './publish'
# package: './[project dir]'
```

Yet no matter what I do I wwwroot remains empty. Logs all say it was successfully deployed with no errors