Hi
Issue solved
it seems Azure Container Instances removes custom HTTP response headers: trying to browse /api/plugins/download?plugin=cshrap URL result in correct download but in the response the SonarMD5 header was missing.
Since I wasn’t able to change this behaviour, I deployed SonarQube on Azure AppService: in this case, however, I had to use version 8.9 of SonarQube because I ran into this issue [SONAR-15167] SonarQube 9.0 Images fail on old docker runtimes - SonarSource
Alberto