Aneros keeps coming out/no pleaseure from direct contact

Hey gang, in the past few months, I've been making some decent progress (after 7+ years of little to no progress). In most "good" sessions, my body will want to do certain contractions - the main one being a bearing down/pushing out type contraction. This one is somewhat new to me, but I think it's a good part of my rewiring, as it leads to some pleasure. My body will also do the pulling in contraction, but this one gives little to no pleasure, which seems wrong to me, as I think it's making contact with the prostate during that contraction.

Many times, when my body does the bearing down/pushing out contraction, the Aneros will start to come out. Like I noted above, I feel pleasure during this, so I try to relax, and hope the toy isn't going to come out (though it's hard to fully relax when worrying). I start to feel my pulse in my rectum during this. and that adds to the pleasure, but eventually my toy ends up slowly coming out.

I've heard of others wearing undies so the toy doesn't come out, so I may start to try this, though I still worry that something is not quite right if the only pleasure I get is from the toy coming out.
My reason for posting is to see if others have had this same problem, and how they overcame it. I'm also worried that maybe all the pleasure I'm feeling is anal only, and no pleasure from the prostate.

One suggestion is to start doing kegal exercises. I do about 30, 3 times per day. Hold for 10 seconds/relax for 10 seconds. This will strengthen your pc and other pelvic floor muscles and also wake up the region, possibly increasing the good feelings you experience during your sessions as a bonus.