Doesn't Get Pulled In Anymore

When I first used my Aneros MGX almost 8 years ago I was amazed how once I got it in just past the inner sphincter muscles it got rapidly sucked inside my rectum and I had a massive wet orgasm with no erection. I used the different Aneros products for years and enjoyed them and they were always pulled in by my body. After not using them for a while I wanted to do so again. I find now I have to push the Aneros into place as it's not being pulled in by my body anymore. It's not really as pleasureable either. Why is this? I'm thinking of getting an electric pelvic floor exerciser with an anal probe to tighten up this area again. Maybe this is the problem due to aging and my having been recently diagnosed with Parkinson's disease. Has anyone here done so and had success?