Williams Sound Motiva Personal FM Listening System & Oticon Streamer Pro

Is it possible to use the Motiva 360 transmitter/receiver system with my oticon Streamer Pro 1.3A?

Yes - you can connect the headphone jack of the Motiva receiver to the AUX input-jack at the bottom of the Streamer Pro with a short audio cable 3.5mm jack plug male to male.

I find that if I push the Jack in all the way, it doesn’t work, but if I leave it out about 1/8”, it works fine. Anyone know what kind of Jack I need so this is not necessary?