Not understanding activation with trailing order

I have an issue with trailing stop orders (testing with ETHUSDT):

I have a short position open of -0.005, average price is 241.38
I set a trailing close of +0.005 with activation at 241.33, callback at 0.1%

I receive a message saying the trailing close order has been triggered at 241.49
Then another message saying that the close order has been filled at 241.50

My expectation, when I place the trailing close order at 241.33, is that:

  • the execution price is set at 241.33 * 1.001 = 241.57, if the trade price goes up
  • the execution price goes down, if the trade price goes down

But the trading price did NOT go down enough to move the execution price, so I do not understand why the order was triggered at 241.49, nor why it was filled at 241.50

Also this tutorial has case this case study, which gives situation A that met 2 conditions and then trigger the order.