Just got a Helix Trident, no sensation?

Finally decided to go for the Helix Trident after reading a lot of reviews & comments online.

I put it in and i just don’t feel anything at all, like it’s not even making contact with my prostate or something?

Is this normal or am i doing it wrong?

I’m used to getting fucked – should i have gotten a bigger model than the Helix?

If so, is there any market for “gently used” sex toys (as in, “little old lady only drive it to church οn Sundays”)?