With dynamic light I have around 5ms drawcalls, on the same scene when I swap the movable directional light to stationary and build lighting, draw time increases to 10ms, is this normal?
This could be due to the fact you are using a lot of Per object shadows i.e. Movable dynamic objects casting static and dynamic shadows. I would have to have your project on my end to really see what is going on, as simply changing a lights mobility is not going to produce different results until you rebuild and begin optimizing shadow casting in your scene.
Also something to keep in mind, Movable lights do not use indirect lighting, so when you switch to Stationary you now need to account for the cost of indirect light bounces and the relative cost that comes with using indirect lighting.
I would take a read over the ‘Light Mobility’ documentation we have, as it provides some helpful detailed explanations of each light mobility and their relative functionality and costs of rendering.
Let me know if you have further questions after taking a read through the documentation.