Hi,
after more research i found the solution myself: it is the “delay compensation”-function in N10.3. But it seems to turn off only my UAD plugins, most of the other plugins (VST2 and 3) work with or without delay comp.
BUT: in N8.3 the UAD plugs worked in the insert slot of audio or instrument tracks regardless of the delay compensation status (on or off, in both cases it worked).
Is this really a feature or just a bug? Would prefer the way it worked in N8.3
Greetings.