In the first version of Cubase 12.0.x controlling of MIDI tracks did not work but the issue is fixed in the while. In Cubase 12.0.52 controlling MIDI tracks is working fine. If I remember it right, than it was fixed in 12.0.50. Controlling effect channels is still not working.
I would expect that Nuendo 12.0.52 features the same updates and fixes as Cubase 12.0.52. As I don‘t have Nuendo I can not try this.
Br
Werner