A Microsoft file hosting and synchronization service.
I have sent the below via the OneDrive app Report a Problem facility. I encourage all iOS device users who utilise OneDrive to do the same - feel free to copy and paste.
“Because of changes made by both Apple and Microsoft it is no longer possible to write to OneDrive via the Save to Files option in iOS. Sharing and selecting the OneDrive app still works but this is not always available e.g. if one wants to move a file from iCloud Drive to OneDrive utilising the Files app.
I have spoken to Apple and they claim that the changes (first introduced in iOS 14.4.1) were based in security and, as such, they will not reverse the changes. So, it is up to Microsoft to update OneDrive to allow write authentication via the iOS Save to Files function.
Can this please be done ASAP for the millions of iOS device users that also use OneDrive?
Feel free to contact me for more information.”