by a mistake I changed the right view to a saved perspective view. Per _undoview I jumped back to the right view, but now the right view can be easy turned per RMB. Could be great if it can be undo to the standard behavior where the RMB doesn’t tun the view.
Sidenote: great to see that undo restore the previous viewport name.
The reason this happens is that the cplane is unaffected by undoview. Parallel views rotate by default when cplane z is not exactly the same as camera direction.