VST instruments reset back to default


I’m using Cubase Pro 9.5. Most of the VST instruments works flawlessly, but for example some of the Native Instruments stuff changes automatically back to default settings & sound whenever the song or loop restarts. Which of course makes them pretty much useless. There has been the same problem with some other instruments as well so I don’t think it’s an NI related issue really, but something else.

I tried to seek help on the NI forum but no luck there.

Anybody has any idea how to tackle this issue? Many thanks!