I recently updated to 4.02 and have noticed a huge lag when switching between performances and even between some patches in the same performance. I will stick with it for now and hope an update comes soon. A lot of my delay setting are messed up now which isn't that much of a surprise since a lot was done with the delays. I have also noticed that changing the delay mix on one patch in a performance seemed to affect the delay mix in another patch. Could have been something else though so I am not sure about that one yet.
Is your kemper connected with your computer and RigManager is running? If RM is running I have also a delay as you said.