After Shaving My Mustache, One Corner Won’t Grow Back!

I have always had patches of hair missing from my beard but last year I grew out my mustache for a month during November. After shaving it off the left corner will not grow back. It is now uneven and I’m not sure way, it has always been full. Is there any reason for this hair loss?

You should be looked at by a dermatologist. Patches of hair loss may reflect an autoimmune process such as alopecia areata, or it could be something as simple as being related to stress. You need a diagnosis by an expert at the minimum.