i'll add to ths post since it's so basic. The Clan boss is not lossing any of it's HP meter during and after battle. in the first shot, this is taken at turn 10, when the boss starts killing off my team. see the full HP meter?

the next shot is the screenshot of how much damage my team did.

the final shot shows the HP meter of the clan boss on my clan page. 

As you can see, no damage shown for the day, even though 5 mil damage was done by just two of us in the clan. against the Easy boss no less. 

btw, i'm running this on a Samsung Galaxy tab S4, with andriod 9.0.