Custom action DLL built w/ Wix 3.11 fails w/ error 800700C1 w/ AzureSignTool

[alcosml]

We have a custom action project that outputs <project-name>.CA.dll, however this DLL, when signed w/ AzureSignTool, throws the ff. error:

 --- Starting sign tool (online) for <redacted>.CA.dll...
info: AzureSignTool.SignCommand[0]
      Signing file.
fail: AzureSignTool.SignCommand[0]
      Signing failed with error 800700C1.
info: AzureSignTool.SignCommand[0]
      Stopping file signing.
info: AzureSignTool.SignCommand[0]
      Successful operations: 0
info: AzureSignTool.SignCommand[0]
      Failed operations: 1

I'm not sure what causes this as other DLLs not built using Wix toolset doesn't have that issue, so I'm posting this here in case anyone has any idea. Thanks in advance.

[alcosml]

Found the fix here