It's been ages those sets stop working at some point when you use them in PvP and this issue is still not fixed...
I would like to use them in battleground but they just work only once till I die then no more and with those new tiny maps there is no way to ever fix that bug ourself by unslot and slot again unless we are in a 8v8 in one of those rare large map and the fights are on the ennemies spawn or between rounds in deathmatch 4v4.
Please consider working on fixing those in your next "Update 44 Incremental Patch" as it's also a lot Battleground related.
An Imperial Cow Warden | PC-EU