Depending on what style slip float your using I'm wondering if braid would cut into the hole in the bobber, causing issues with the bait sinking.
I've had issues with the cheaper bobbers that just have a hole in the plastic with even mono cutting into the hole and not letting the bait drop smoothly. I've mostly gone to the Thill slip bobber that has the brass insert in the top of the bobber.
If your not using a bobber with an insert look at the hole under magnification, maybe your line is cutting into the bobber material causing the issue.
This video talks about the issue. link goes to Thill facebook page
https://www.google.com/url?sa=t&rct=...u&opi=89978449