I believe the his has been broached previously. Your second increment won’t show if it started after the first increment. i.e. 25m in 28 days and 25m in 30 days. So you’ll only see the shortest time one.
You purchased the second increment after the cycle had already started. You won't be receiving the benefit of the next increment if you purchase them after the start of the cycle. So this is indeed correct, you will only be receiving the payout for 1st increment after 28 days. Upon withdrawing your payout, the next cycle will start and if you have 3 increments at that point, it will pay for 3 increments at the end of the next 31 days cycle.
This is necessary otherwise people would just buy 10 increments on the 30th day.