Unfortunately the Bluetooth implementation in the Roger devices does not play nice with the Bluetooth in the Marvels. When using Marvel it’s recommended to use the Bluetooth feature in Marvel and disable it in the Roger mic. The iN microphones does not have Bluetooth at all.
I’ve heard rumors of some users having success with placing the mobile phone much closer to the hearing aid than the Roger mic (it could possibly be the other way around), so they do not interfere as much. I have not verified this, so I cannot say how well it works. But it’s something that could be tried.