If is a muscle or issue, like your hands wont physically do what it’s supposed to, start with a full upper body stretch. Definitely focus more on hand and forearm stretches, but also do back, shoulders, lats, etc. Stretch everything, this always gives me more control of my playing and all my muscle systems seem to work together better.
After that, like everyone says, take it slow. Make every hand movement very deliberate and on purpose. Also with sweeping and economy picking, it’s really good to work on your rest stroke which is picking and letting the pick land on the next string and stop, or “rest”. Practicing this up and down give you more control over your sweeps and economy picking. It also makes your notes more defined and makes them sound more “confident”, if that makes any sense.