That’s never been a problem. I don’t use Microsoft’s online storage for this purpose or their system. I AM a Windows user with a OneDrive account, though. ON my phone, I am signed in to Microsoft account. When the document on my phone is read only, I simply click "save as" and create a compatible format, and save it to my phone.
Recently got a new tablet, downloaded MS Word, just like on my phone, downloaded the documents I use and tried to edit after signing into my MS account for Windows. It tells me I cannot save documents at all without being a 365 subscriber. Won’t let me save in any format in any way, even locally on the device. So, what has changed? Why can I do it on my phone and not my tablet?