Gif picture problem in Storyline 360

Hello.

I meet a problem with gif pictures on Storyline 360.

In Storyline 360, I need to insert animated pictures with transparent background (eye blinking of the character) in Gif format. (given that swf format is not anymore supported in Storyline 360)

In storyline 1 and 2 I did it with a swf file.

 
Therefore I created an animated Gif from my .fla file.
My gif works properly.

 When I import it in Storyline 360, it works but it has a lot of aliasing.
Especially when I resize it smaller.

I made some test in Storyline 1 and Storyline 2 and I have not this aliasing problem, it works great when I resize it smaller.

I also tested the gif in PowerPoint and no aliasing problem when I resize the picture smaller.

 

Therefore, I dare to think that this is a problem proper of Storyline 360.

To make it more meaningful, I attached the Story 360 file.

Slide 1: gif and png in original size without resizing (we can already see a slight aliasing on the gif)

Slide 2: gif and png reduced (we can see that the gif has a lot of aliasing)

I also attached the Storyline 2 file, we can observe that there is no difference (no aliasing) between the reduced gif and png.

 

This aliasing problem is very embarrassing for us, because we use this gif in all of our courses.

 Can somebody can tell me how I can resolve this problem?

 

Thank you.

Best regards.

Nicolas.