Gold bonus with hero's items is not taken into account in Ninja Event

I just noticed that the gold bonus perk on my hero’s items isn’t taken into account after finishing an island. Normally my loot is doubled but this time I only got around 600k and a bit while the loot that I could win was around 440k. Is anyone aware of this issue? Or is this by design and it’s simply just how the game works. If so, why?

This was noticed since the first ninja event, and it bothers me how they haven’t fixed it…

i guess i am facing the prob for just this war season. Earlier i got gold bonus from items too.

sorry *ninja event