Jun 19, 2018 - 02:52 AM
The route to install is different and so are the licensing terms (which i am sure you read prior to installation)
If you have purchased through a Volume license contract and used your Office VL to "from SA" across to 365 and you have continuous SA coverage since then there is a clause within the Product Terms which does allow you to revert back to VL licensing. However i am advised that this is a business desk desicion within Microsoft depending on your company size. Given that the M365 now allows VL usage or 365 usage (customer choice) this is rarely an issue for most companies.
If you have purchased via box product/online download - you need to contact the people you purchased it from.
Jun 19, 2018 - 09:35 AM
"Enterprise Agreement customers who transitioned to an Online Service or who purchased a From SA subscription License in lieu of renewing SA may reattach SA to a License at anniversary or renewal without purchasing a new License."
This should be available to any Enterprise Agreement customer.
With Microsoft 365, From SA SKUs are required for the option to install Office Professional Plus. This is available via Enterprise Agreement & MPSA.