There is a bug in clan war xp. The 10 and 25 xp are given at very low stars scored, instead of 40% and 60% of total stars available in clan war.
This bug exists in my both accounts, meaning it is not an isolated case. For a 15 vs 15 clan war (iOS device), only 2 and 4 stars need to be scored to gain 10 and 25 xp respectively. In my another account of 40 vs 40 clan war (Android device), only 6 and 12 stars stated to be scored to gain 10 and 25 xp respectively.
