Possibly two reasons. One, something has happened to the return spring. Or!, something a bit easier. Leave your bike on the side stand. Put it in neutral. Now bend down and look at the shift rod that is under the chrome side cover. With your hand try to shift down to first while watching the rod. I have seen some bind up on the bottom of the cover causing it to stick. If it does, well, it has either been bent or improperly adjusted. Take a look.My shifter has just recently started to stick in the down position instead of popping back up when down shifting. If nudged it will pop back to a normal position. Feels like it hangs up or spring is binding somewhere. Not sure which spring on the inside. Has anyone had this issue.