Birdlocked discussion

Hi there, As chastity becomes an increasingly important part of my life, I’ve discussed it with my girlfriend and purchased a Birdlocked to test on my own before going further—she’s unaware of that last detail. I managed to get the device fitted after several attempts, but once inside, it doesn’t remain secure as seen in many photos; specifically, the ring should rest against my stomach. Instead, when I attempt an erection, my penis tugs at the cage slightly, compressing my balls and causing the ring to shift about two inches away from my body. Once this happens, I struggle to return it to its proper position. The discomfort isn’t severe, but it renders the cage visible, which could be a significant problem if my partner decides to take on the role of keyholder. Is this a common issue for others? Did I overlook something or make an error in fitting? Do you have any suggestions? I considered size might be the culprit, and according to the chart, I seem correctly sized. Could it be that Birdlocked isn’t suitable for me at all? That would be disappointing because I really worry about cages interfering with sleep quality, especially since my job is physically demanding. I hope this description covers everything… Regardless, thank you in advance for any help regarding this issue.