I am on Nuendo 11 on a Mac and I have had the following issue I think since Cubase 8 or 9 and it is happening in Nuendo 11 as well.
When I export a tempo track from a project and import it into another project, the tempo changes do not show up in the tempo lane of the new project. They show up in the inspector though. But, I first have to delete the tempo track and create a new one. Then everything is displayed alright.
Anyone else having the same problem?