Bliz, you have bugged your own delves. They are no longer solo friendly and even with 4 people and Brand as our fifth, we got instant wiped only only a level 4 delve.
You can see my most recent post regarding this here: Delves Tuning, Sept 12th - #1005 by Nyls-anvilmar
I refuse to go back into your nightmare “solo friendly” delves until you fix your mess.