Some strange physics behaviour after I do stopRenderLoop()

Questions
1

I have a playground here
Look at the console. When you just run this code you see at the start:
dt = 16, dt = 1, dt = 2, dt = 17, ....

But after 5 seconds it stops by setTimeout() with stopRenderLoop() and starts again with runRenderLoop(), there are no any dt = 1 or 2ms, now dt-values are only:
dt = 16, 17, 17, 16, ....

It looks after restarting the loop physics runs slower than in works before. Maybe some physics sub-steps are missing.
Why does it happen? Should I restart physics somehow?

2

Adding @Cedric and @carolhmj

3

I have no idea why it happens.
Some questions to have a better idea:

  • does it happen with other observable like on before render?
  • did you try to use Chrome profiling tool to see what happens?
  • Are you sure there is only one renderloop active at first?
  • can 2 frames be computed between 2 vsync thus having only 1ms (and < I guess) for the second frame?