Instagram problems

Did you delete the folder that Instagram made on your phone? If there are any corrupt files in there, it will cause the app to crash or behave oddly. Especially if factory resetting the phone did not wipe that folder. (Android/data/com.instagram.android)

If that didn't work, did you email the developer of Instagram and ask if they have a solution to the issue? More often times than not that is your best option if you've tried everything else.

 

I have heard people having issues with the latest instagram version and phones like the Note 3 and Galaxy S4 about posting videos containing the front facing camera.

I would suggest to do what Petrah said, contact the developer.