Taskbar autohide breaks PortableApps menu

I have two computers running Windows 10 Pro. Both computers have the taskbar set to auto hide in desktop mode. In the last day or so, the PortableApps menu has started behaving badly on both computers. When i click on the PortableApps icon on the menu, and move the mouse toward the menu, the menu immediately disappears. If I turn off auto hide, the PortableApps menu behaves normally.

As I said, this is new behavior and NOT related to any platform update. I have been using PortableApps.com in this configuration for years with no problems.