How to re-install EAP 802.1x authentication methods?
I had a similar problem with the phone. The EAP method is greyed out with the sim option selected. I did however manage to change it after playing with it for some time. For reasons unknown, the option did eventually become available to me by just trying to modify the settings then exiting and repeating that process. Once the option becomes available it did not remain available for long. As far as I looked there is no current fix, I hope this works for you too.

Hope you come right with you problem.
Cheers