The latest version of i-TURTLE has a new feature. You can switch the TURTLE TTL to Manual and back. You have to use the backlight switch to change the mode. The left side DIP switch part 1. DIP is set the default mode. When the camera goes to sleep the TURTLE switch back the mode to the default.
Some series for exapmple the Nikon D500 switch the backlight during the expo. So the correct picture we have to switch of the backlight on the camera “d9” menu.
Here is the menu where we can find this setting.