Or your pick technique. How tight you hold it, how far from the tip, how deep do you dig in.. hand placement wrist action..
Lots of thing that we can't see of what you are doing.. Take a chord or two or no chord at all and practice strumming real easy and loose.. Note all the thing in your strum to be correct..
You may just be a fingerpicker but it's more fun if you can play different styles.
Hang in there, you'll come up with a good way to express yourself..