Hey! I’ve had this problem and I’m happy to help! There’s two things you can do. You can get a new toothbrush and brush under the analog stick, doing this will remove any dust! If that doesn’t work contact Nintendo, if the joycons came with the console, and it’s been under a year since you’ve purchased the switch. You can call Nintendo, set up a repair, and they can repair it for you! (If you bought them separately you need to have your receipt for proof of purchase!) However you can also ask them to replace the joycon instead, so instead of fixing the old one, they just send you a new one! Hope this helps!!