@eveh have you tried to change the settings at
ACP > Settings > Uploads ?
try adding .gif to the list...
alternatively, you can use "tenor gif" plugin...
Gif Making GIF
The problem is when uploading images with iphone, the latest image upload reflects previous image upload.
Tested on iphone 4s 5 and 6 browser safari and chrome. While uploading first picture everything seems to
function fine, but after second image is uploaded the first one gets overwritten with second.
Easy to replicate.