Chastity device discussions and reviews discussion

Contrary to what my picture shows, I am currently lock in a Birdlocked Neo and really enjoying it (even though I’m self-locking). My question is has anyone else had the problem for their foreskin moving forwards in the device? The issue is that it gets to the vent holes at the end where they stick through and rub. I have to remove myself from the tube, pull back, and reinsert. Is there a way to stop this happening or fix it without coming out?