EL-16FE Dual Zoom Attachment Doesn't Work

I've been trying to flesh out my assault class and I finally got 250 kills with the last gun, the EL-16FE, and was supposed to be rewarded with the dual zoom scope attachment. I claimed the reward and the attachment icon on my customization screen turned bright white like normal. However when I attempt to use the dual zoom in an actual game it does absolutely nothing. When I use the same attachment on the A-280 it works perfectly fine, I don't understand why it won't work on the EL-16FE. Can anyone offer a solution?