This has been reported before and was broken with a recent Instagram update. You will need to wait for Instagram to provide another update to fix the problem or contact them with the issue. It is apparent that they let there users be bug testers since they have updated their app 13 times in the last month. Each time they may fix one problem, but introduce another. They are not known for providing useful support, but you can try here:
https://help.instagram.com
Sometimes writing a review on the App Store will provide a quicker response as those posts are viewable by everyone.