Hey there.
This is a common bug on certain armors, that usually are created or not found on the tool set or modified on any way from a GM ( This condition can be found on drops too ) .
The first recomendation on this would be to actually ox the armor, and then try again, if this doesn't fix it, Get with an Gm for an exchange of the bugged armor.
That must fix it. But try the oxing first and then post here about the results, If it doesn't work I'll try to get with you to see the problem if no other gm beats me to it.
Hope this is helpful
Cheers
Redeemer .