Dragging/Dropping documents into a view grouped by a particular property "(any value)" adds the multi-valued property and prefills it instead of prefilling the single valued property that is already on the metadata card. How do we change this?

I believe you would need to update the view grouping to use the specific property you want to populate. Otherwise, with the "any property" grouping M‑Files will default to the built-in multi-select property that is automatically created with the object type, if I recall correctly.

Thanks for the reply Joonas.  If I group by the specific property instead of the "any property" grouping than many documents (those that just have Policies and not Policy) do not show up in the view alongside those that match Policy.  So our users are unhappy that they can't see all the documents.  So ideally, here's what we want 1) a view where all documents with the same policy number in either Policy or Policies show up grouped in the same view and 2) when we drag/drop into this view, the Policy property is automatically set.  Joonas, are you saying this isn't possible in the same view?

As far as I'm aware, this is not directly possible. When using the “any property” grouping, M-Files will always populate the default multi-select property when files are drag-dropped to the view.

As a potential workaround, you could explore copying the value from the multi-select property to your preferred Policy property. However, this approach may lead to some user confusion, as the multi-select property would still appear populated initially.