UnknownUser_ZjYrq9onjT - The changes in charging times you are experiencing shall mostly be down to the Phone trying to protect itself against heat. An unfortunate by-product of charging is heat, so if you use the phone whilst charging, the other usual processes shall have additional heat to deal with, therefore the Phone tells the charger to draw less power, to protect the battery, the chip etc.
As most areas of the world are in their summer months, the charging speeds shall be affected, also. Unfortunately, the best thing to do is to leave your phone alone whilst charging, and/or do so in a cooler area/at night.
