if you slip bobber was doing ok out of the water but not in, you likely have a slit or groove cut in the bead or top of the bobber that your line gets caught in when casted out from shore and the line is at an angle from the rod tip to the top of the bobber. Most cheap slip bobbers have this issue after a few outings with them. I replace all the plastic beads in the top of the bobbers I use with either glass or metal to prevent the 'groove' issue. Nothing worse than trying to fish 18ft down and your line won't go down thru the bobber after you cast it out.
I don't even use the beads and have no issues.
I am not talking about the extra bead that alot of bobbers come with that you are supposed to put on above the bobber. I am talking about the cheap plastic ones some bobbers put in the top of the post. 2-4 lb line will cut gooves into those plastic beads. It has been happening for 30 years to me until I started pulling them out and replacing them with metal or glass ones, then I have no issues. Are you saying you just remove the bead completely? If so, what keeps your slip knot from going right through the post with that big hole in the top?
My slip bobbers don't have a bead on top. Just a tube with a small hole. Knot doesn't go through. I'll take a pic tomorrow and post it.
Hers the trick i use. Take a pop rivet,remove the nail, cut the red bead off end of bobber, slide a rivet collar on both ends of bobber, drop of glue and you'll never have trouble with line cutting groove again and a whole lot cheaper than a stans bobber and works much better because of the rivet on both ends. Use as big a bobber you want and any size line.
Lighter the line the greater chance of the line cutting either end of the bobbers. Stans bobber work well for the top other than they have a small opening compared to a rivet. A revit on both ends isn't as hard as it seems as long as you twist your line as you slide end thru bobber. The dbl revit allows you to use less lead or use heavier line to get down fast. You'll be able to use a smaller bobber for those finicky biters.