One thing that jumps out to me, is she isn't solid on "here"
Try correcting her every time she stalls (drops the bumper) on her return. "here" means here now.
You could try keeping a leash on her and pull her in after she gets the bumper in her mouth. If she drops, keep pulling her in without giving her the chance to pick it back up. Then, walk her back out and ear pinch to bumper.
As far as holding bumpers on the ends, I'm with the group that doesn't think it really matters, will likely fix itself, and isn't a concern when retrieving birds.
My $0.02 from a limited experienced background and zero experience with Chessies.
Edited by TXPride (02/09/15 11:12 AM)