Please, let Support team know about this bug.

And I'll try to check it on my Android.

Everything works as it should on my Android 4.2.

I'm having the same problem.  I play on an apple ipad ios 9.3.1. I have upgraded the dragon's hide and chariots of fire to level 10. The game reports that i will have a 15% train speed upgrade for my infantry and cavalry units. However, when I activate those arts, my training speed doesn't match what I expected. For example, a pikeman normally takes 5 minutes (300 seconds) to produce. With the 15% train boost, i would expect the training time to drop 45 seconds to 4minutes and 15 seconds. However, the game reports that my training speed is 4 minutes 20 seconds. According to my calculator, that's a 13.3% training boost. For the cavalry, a nomad normally takes 20 minutes (1200 seconds) to produce. 15% of 1200 is 180 so I would expect the training speed to drop to 1020 seconds or 17 minutes. However the game reports that it will take 17min 23 seconds to train a nomad. This is 13.08% speed reduction. Are the results I am expecting incorrect?

I tried creating a bug report but the web site keeps telling me that a necessary field isn't filled. I tried multiple times without success. I think it was the screenshot field but i'm not certain. Is there anyway someone can get this information to the support team?

I'm having the same problem.  I play on an apple ipad ios 9.3.1. I have upgraded the dragon's hide and chariots of fire to level 10. The game reports that i will have a 15% train speed upgrade for my infantry and cavalry units. However, when I activate those arts, my training speed doesn't match what I expected. For example, a pikeman normally takes 5 minutes (300 seconds) to produce. With the 15% train boost, i would expect the training time to drop 45 seconds to 4minutes and 15 seconds. However, the game reports that my training speed is 4 minutes 20 seconds. According to my calculator, that's a 13.3% training boost. For the cavalry, a nomad normally takes 20 minutes (1200 seconds) to produce. 15% of 1200 is 180 so I would expect the training speed to drop to 1020 seconds or 17 minutes. However the game reports that it will take 17min 23 seconds to train a nomad. This is 13.08% speed reduction. Are the results I am expecting incorrect?

I tried creating a bug report but the web site keeps telling me that a necessary field isn't filled. I tried multiple times without success. I think it was the screenshot field but i'm not certain. Is there anyway someone can get this information to the support team?