Frequent cold sores (over 4 in about 60 days) , could there be an underlying issue causing these ?

Possibly: Exactly why they occur more frequently in some people was not known, but now new research suggests some of us may have a genetic predisposition to frequent, severe cold sores. There may also be some other factors that may contribute to frequent outbreaks such as gluten intolerance, fever, menstruation, stress, fatigue and exposure to the sun.

Herpes Virus: Cold sores are caused by the herpes simplex virus, which is not eliminated from your body after an outbreak heals. Instead it "hides" inside nerves, and becomes active again when the nerve is overstimulated. Over time the frequency of outbreaks usually lessens. Your rash of outbreaks may be due initial infection with the virus, or the nerves being overstimulated more frequently lately.