Staying In My CB2K for a Longer Stretch

This time around, I managed to keep the device on for 20 days before a pinch point got too much and forced me to take it off. I expect to put it back in tomorrow or the next day, keeping up with the honor system until then. Is this happening because my ring is too big? It feels like there’s quite a bit of extra space inside. I’m considering picking up that 1 7/8 inch ring from A&L Enterprises for $20. The one I had was actually thrown out by my mother-in-law—who can be such a pain!—but let’s leave her story alone. Anyway, the used MM Jailbird I plan to buy comes with a 1 7/8 inch ring, and their website claims it works similarly to the CB2K. So theoretically, this size should fit me correctly?