Happened to me as well. Last TW, joined up. I even double-checked later that day (usually do), overnight, guild trying to get a hold of me, too late to realize I had been removed and couldn't participate in TW. Glad I'm not the only one only because they know I'm not crazy or lazy, but, unhappy we're still having people suffer this. There goes some critical progression loot (read Zeta mats).
Reported this last time and was marked closed minutes after. Again, a new war, still a greyed out join button. Tap it once to make it show up green. Tap again to join.
I had this problem with the Territory War that started today.
This was initially reported in June, it is now September, any update as to when you are going to fix this problem @EA ?