Using the EasingDirection “InOut” with the EasingStyle “Back” causes some unexpected behavior as seen in the Gif below
As you can see, the brick does a rather odd “snap” back to or beyond its original position and in doing so cancels the ‘Out’ portion of the EasingDirection. In the Gif above I am using CFrame and have tested it on most of the BaseParts and the Camera, all producing the same result. I’ve also tested this using Position, Size, and Transparency all producing the same bug. I have also tested this both locally and server side.
For your convenience here’s a place file to demonstrate this in real time. Tween script is located in ServerScriptService.
If you can, please put together a place file which you can reproduce this issue with. I can then take a look and see if you’re doing something different, or see if there’s something more subtle going on here.
I’ve created a test place for you to use to replicate the issue. All you need to do is load the place, play it, and press the move button to tween the GUI with the InOut and Back arguments.
You can look into the GUI to investigate the issue if you need. I added a basic bool value and another value to dictate which side of the screen it is on. Other than that, the only thing the script is doing is tweening the GUI from one side of the screen to another.