Did a quick google search, found these on XDA & reddit.
I believe the issue is global, only on Samsung devices and does not comes from Instagram.
Just posted this to the reddit thread, but want to keep feedback here as it seems to be a Samsung issue!
Let me complicate things. Not all accounts will refuse to work. My s7edge that I gave to my girlfriend has this problem, but only with her account and regardless of content. It loops on any type of story she tries, but with mine it works perfectly on everything! I successfully post something on mine, switch accounts to hers and it doesn't work... It happened before we changed phones and after the reset to make the change. So, no solution from here and the problem is horrible. We sent a lot of complaints to Instagram with no reply...
Hello !, I found the solution, the only thing to do is join the instagram beta tester program in the Play Store, once done, update the application that will appear, and voila !, instagram will work again with the videos and the gif !, I attached a video, is in Spanish but visually you can understand if there is any doubt
Greetings from Mexico, I hope it works!
Samsung became ***** and it's not worth it buying another flagship of theirs. this is a global issue for millions of customers and they don't bother to offer a solution even after more than a year. They are too focused on marketing new devices and forget about their loyal customers. Don't give a ***** about them, just like they don't give one about me (or us) therefore I'm going to throw this crappy S7 edge and get a Huawei. Price vs quality is much better there