Difficulties with wearing a device? discussion

Hello, I’ve had an MM pet trap set up for a while and have just resumed using it after being away from it for quite some time. I am currently in the middle of a two-week lock-up period with scheduled pauses to clean it, and I’m noticing some chafing on the underside of my penis where the rear edge of the tube rests. Do you have any thoughts? Is the gap too narrow? Thank you!