When dragging items between layers, sometimes a wrong set of items is moved. I.e. if I select items 1,2,3,4,5 of a layer and drag them to another layer, items 16,17,18,19,20 move instead.
The workaround seems to be to drag items within the layer to check that the right ones move before committing to the full move.
I’ll post a video if I can.
Appears in version 4.8.2 in iPadOS