Game.Loop:
  var logicInterval = worldRenderer != null && worldRenderer.World.Timestep != 0 ? worldRenderer.World.Timestep : Timestep;

  // World.Timestep - 20 - 50ms, Timestep: 40 ms
  if (now >= nextLogic)
					{
						nextLogic += logicInterval;

						LogicTick();
					}

LogicTick
  InnerLogicTick(OrderManager);

static void InnerLogicTick(OrderManager orderManager)
  if (uiTickDelta >= Timestep)  // always Timestep (40), with logicInterval 50 (game slow speed) this isn't called each 40 ms as expected
    // Ui.LastTickTime and Viewport.TicksSinceLastMove are updated later, causing e.g. flickering of tooltip due to IsVisible = () => Viewport.TicksSinceLastMove >= TooltipDelay;
    Ui.Tick();

  if (worldTimestep != 0 && worldTickDelta >= worldTimestep)  // timestep consistent with Game.Loop logicInterval
    World.Tick(); // called e.g. each 20 - 50 ms