Good sexual side effect from finasteride

I don’t know if this is happening to anyone else but on .5 finasteride I have been able to last longer, my penis is harder, and it has gotten a little longer (I was not well endowed before so I can tell). Is this normal I always hear the opposite of this? It’s only been a month and a half. I would like to know why this is happening

One of my son’s had this side effect and an increased sex drive as well. He loved the drug!