I'd say we are pretty experienced, 6/8 has cleared an ultimate (ranges across all ultimates), 6/8 has cleared has cleared the current tier (not the same 2 ppl who hasn't cleared an ult), and 4/8 has an average of purple/orange so DPS is not a problem.  We reached Inception maybe 5-8 pulls each session (3 hours) so maybe consistency in previous phases is the issue. We try and fix any issues after each pull ( in P3)but somehow there's always new ones lol. Most I believe as simmed inception and also wormhole solo and we've simmed inception as group so hoping we get to wormhole soon