How to move several shape points in the same time?

When selected shape points, I used to move them either by drag mouse or press up or down arrow on keyboard in OmniGraffle version 6.
Now I need to change and try on OmniGraffle version 7 (because version 6 in macOS High Sierra cannot export PNG), it doesn’t work the same way. I have looked many places for solution but no one can tell.

Could you please show me the way how to move several shape points in the same time in OmniGraffle version 7?

You should be able to move multiple points the same way, so this is unexpected behavior. This issue has been reported to the OmniGraffle team. I’m sorry for the inconvenience. When we release updates that include bug fixes, the release notes are posted at https://www.omnigroup.com/releasenotes/omnigraffle. As a workaround, you should be able to keep OmniGraffle 6 and OmniGraffle 7 on the same machine. If you need to download it again, we have older versions posted at https://www.omnigroup.com/download/.

I’ve had this same problem since October of 2016 when I first reported it here. It’s the arrow keys that I need, nudging the points around rather than moving the entire shape.

(Here: Nudging Shape Points)

Many hours of workarounds since then, sadly.