Upload coverage information to SonarCloud from coverlet for C# project - yaml

Question

I'm trying to collect coverage info and publish it to SonarCloud for my C# project, using GitHub Actions as my CI pipeline. The execution is very simple, basically trying to execute tests for all projects, merging all coverage files:
run: |
.\.sonar\scanner\dotnet-sonarscanner begin /k:"LanguageDev_Yoakke" /o:"languagedev" /d:sonar.login="${{ secrets.SONAR_TOKEN }}" /d:sonar.host.url="https://sonarcloud.io" /d:sonar.cs.opencover.reportsPaths="CoverageResults/coverage.opencover.xml" /d:"sonar.verbose=true"
dotnet build
dotnet test /p:CollectCoverage=true /p:CoverletOutput="../CoverageResults/" /p:MergeWith="../CoverageResults/coverage.json" /p:CoverletOutputFormat=\"opencover,json\" /maxcpucount:1
.\.sonar\scanner\dotnet-sonarscanner end /d:sonar.login="${{ secrets.SONAR_TOKEN }}"
Note, that I do need to output in both opencover and json formats. coverlet only seems to merge properly is json is among the output formats, so it can then convert that to opencover in the end.
The problem is, this generates no coverage information on the CI - downloading artifacts show no generated folder or files. However, if just pass /p:CoverletOutputFormat=opencover, all coverage information is generated on the CI - but not merged properly because of no json output.
Locally, the command
dotnet test /p:CollectCoverage=true /p:CoverletOutput="../CoverageResults/" /p:MergeWith="../CoverageResults/coverage.json" /p:CoverletOutputFormat=\"opencover,json\" /maxcpucount:1
just works and generates the proper coverage XML file.
What could be the problem, why does it not work with both coverage formats specified for the CI? Initially I thought that I do not know about escaping quotes in YAML but this does not seem to be the case here.