Unable to use Package Manager with SSL interception

I'm using Unity on OSX behind a corporate firewall with SSL interception, and was very excited to see that the 2019.1 documentation includes information on proxy setup for this case. Unfortunately, after installing 2019.1, creating /Library/Application Support/Unity/config/upm-config.json, and pointing it to a PEM file containing our custom CA, package manager still has problems with the SSL interception. Any thoughts?

Thanks in advance,
Tim

~/Library/Logs/Unity/Editor.log:

[Package Manager] self signed certificate in certificate chain
Cannot perform upm operation: self signed certificate in certificate chain [NotFound]
UnityEngine.DebugLogHandler:Internal_Log(LogType, LogOption, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:LogError(Object)
UnityEditor.PackageManager.UI.UpmBaseOperation:OnError(Error) (at /Applications/Unity 2019.1.0/Unity.app/Contents/Resources/PackageManager/BuiltInPackages/com.unity.package-manager-ui/Editor/Sources/Services/Upm/UpmBaseOperation.cs:198)
UnityEditor.PackageManager.UI.UpmBaseOperationrogress() (at /Applications/Unity 2019.1.0/Unity.app/Contents/Resources/PackageManager/BuiltInPackages/com.unity.package-manager-ui/Editor/Sources/Services/Upm/UpmBaseOperation.cs:182)
UnityEditor.EditorApplication:Internal_CallUpdateFunctions() (at /Users/builduser/buildslave/unity/build/Editor/Mono/EditorApplication.cs:200)

(Filename: /Applications/Unity 2019.1.0/Unity.app/Contents/Resources/PackageManager/BuiltInPackages/com.unity.package-manager-ui/Editor/Sources/Services/Upm/UpmBaseOperation.cs Line: 198)

Error searching packages online.
UnityEngine.DebugLogHandler:Internal_Log(LogType, LogOption, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:LogError(Object)
UnityEditor.PackageManager.UI.<>c:<FetchSearchCache>b__53_1(Error) (at /Applications/Unity 2019.1.0/Unity.app/Contents/Resources/PackageManager/BuiltInPackages/com.unity.package-manager-ui/Editor/Sources/Services/Packages/PackageCollection.cs:222)
UnityEditor.PackageManager.UI.UpmBaseOperation:OnError(Error) (at /Applications/Unity 2019.1.0/Unity.app/Contents/Resources/PackageManager/BuiltInPackages/com.unity.package-manager-ui/Editor/Sources/Services/Upm/UpmBaseOperation.cs:200)
UnityEditor.PackageManager.UI.UpmBaseOperationrogress() (at /Applications/Unity 2019.1.0/Unity.app/Contents/Resources/PackageManager/BuiltInPackages/com.unity.package-manager-ui/Editor/Sources/Services/Upm/UpmBaseOperation.cs:182)
UnityEditor.EditorApplication:Internal_CallUpdateFunctions() (at /Users/builduser/buildslave/unity/build/Editor/Mono/EditorApplication.cs:200)

(Filename: /Applications/Unity 2019.1.0/Unity.app/Contents/Resources/PackageManager/BuiltInPackages/com.unity.package-manager-ui/Editor/Sources/Services/Packages/PackageCollection.cs Line: 222)

 

Can you please also send me the workaround for 2019.1 (but on Windows)?