Pretty sure that you are describing is the cast control cap spacer. So if you look at your cast control cap or tension knob as some call it, you will notice that when you unscrew it there are 2 small flat pieces that sits inside of it. It is likely worn in some fassion if they are both there. The remedy is you can try turning the spacer over and see if that solves it. Try that first. If that fails you likely need a new one. Also make sure you have both of them that are in the links below. If one or both is missing that is your likely cause. By replacing it, you will be able to adjust the tension so the bait can fall at a faster pace, light speed, or what you are looking for a nice slow gradual fall. Looks like a $4 part and $1.29 a part. If you have several from this reel platform and you think you are going to hang onto them for a while, maybe grab an extra while you are at it. You can see the schematic in the link. I am not sure which parts are worn without looking at them but it may be best to buy one of each.
https://www.ereplacementparts.com/cast-control-spacer-p-1544195.html
https://www.ereplacementparts.com/spool-tension-spacer-p-1540737.html