Just started to use co authoring in the one drive to have simultaneous worksheets, going well.
When giving people permission to view and not edit they are however not able to see the changes in real time.
Is this a bug or a feature.
You need edit permissions for co-authoring, as detailed in the documentation: https://support.office.com/en-us/article/document-collaboration-and-co-authoring-ee1509b4-1f6e-401e-...
Thus I'd assume it's working as expected, once the user refreshes the document he should see the changes you or any other authors have made.