This appears to be an issue with counterattack when shared dmg is activated.
Shown in the pic, I have Wilbur’s shared damage special activated, along with Elena’s counterattack.
The opponent’s Magni attacks Tarlak for 650 total damage which is distributed over my team, dealing 130 dmg to each hero.
Magni, considering Tarlak’s counterattack activation, only takes 115% of the 130 dmg, instead of the 650 total dmg.
For damage to be shared, it needs to be applied at one source first (Tarlak). The counterattack should be based on damage received (650) before its shared/dealt with the team. I believe the counterattack should be for 747 dmg on Magni, instead of 149 dmg.