1raider1: not so. Currently US military and policy convention is to use “Afghan” as the person and the adjective, and “Afghani” only for the currency.
In Dari “Afghan” is the noun and “Afghani” is the adjective, but in current American usage “Afghan” is used. I can’t think of any good reason to call the person an “Afghani”, unless by some weird conflation with “Israel —> Israeli.”
The citizens of Pakistan are called Pakis.
It’s not a weird conflation. What little I learned of Arabic while in Iraq made me believe that the “e” sound is added to the end of words to denote belonging. For instance someone from Iraq is “Iraqi”, someone from Iran is “Irani” (NOT Iranian, as Americans typically say), and the Iraqis even called us “Ameriki” instead of American. Although, in this situation, I guess you would say “Afghanistani” (even though they don’t really speak Arabic in Afghanistan).