Please contact the vendor / person who wrote your authentication script to address this.

The problem in iOS 10 here is that the video component does not recognize cookies that have "no expiration time" set (such as a cookie that is set with a time expiration of 0). We had to make changes to our "Protect" software to no longer use cookies with no set expiration date. Your authentication script vendor will need to update their script to do the same thing.

Once they do this, the movies should play like they did before.