Lag when using shot tracks

Hi, If i create a complex scene with many cameras and characters and animate between cameras using camera cuts (in one single level sequence) there is no lag between cameras.

If i break the scene down into separate shots and put them back together in one sequence as shot tracks, whilst this is the optimal way to work there is a really frustrating lag between shots. For me this is unuseable to assess the edit. Whatever the engine scalability, there is a kind of mini-glitch on every edit. Is there a way around this, or should i give up and just work in one level sequence? Have a missed a setting or set things up wrong? Thanks in advance…

Does pre-roll help?