From what i remember,Madara and Hashirama were in the barrier along with the shinobi alliance when Jubito planned to use 4 big tbb to erase everyone.The Shinobi allaince escape but Hashirama and Madara was left there.Current chapter show that Madara and Hashirama still active in their battle and they also show no sign of injuries.This make me believe that Madara PS was strong enough protect him from the total devastation of the 4 tbb