I don’t know if this is intentional by SG, but:
During Alliance wars - I have not been attacked.
I just gave Aegir Talent Level 8 (Health Bonus +43 health). When I went to the War screen I noticed that Aegir’s health bar is not completely full and shows his health at 1518HP, but since I upgraded him - Aegir’s current full health should be 1561HP
Is it intentional by SG to not immediately update the hero’s stats during War? Or is this a possible bug?