O365 C2R service causing errors

Hi

I am trying to package up O365 (Excel only) 32 bit to run on Win 10 20H2 which has O365 64bit running on it.

I am packaging on a vanilla 1909 OS (not sure if that matters) using version 1.2020.1006.0 of the msix packaging tool.  I can capture up the install of the software fine and Excel itself will open fine after the installation.  The Click to run service is included in the package.

The problem I have is that when I try and install the package on Win 10 20H2 I am getting the failure

"The package installation failed because a version of the service exists outside of APPX packaging. Please contact your software vendor."

error code 0x80073D27

Does anyone know what might be causing this and if there is a fix?  If the C2R service has been included in the package (which it says it has) then why is it complaining about the existence of one on the laptop?

Thanks

Graeme