Pause should only cause a lag, oif the game engine is challenged to much. Because after pause, it tries to start with the normal frame rate. If it cannot keep up with that, it will gradually reduce the frame rate until it can handle all the other interaction again.
Older version had the issue, htat they started the timer before loading was complete, and hence confused the frame rate calculation. (And they lacked proper multithreaded redraws, althoung I am not sure about 112.3). But you should update, the have been many errors fixed since then.