UR-RT2: still hearing dry signal even with muted channel

Hi, I´m using a UR-RT2 interface, Windows 10. When I plug an instrument on channel 1, I hear the dry signal comming from the left speaker, even if I mute the channel on the control pannel. If I plug an instrument on the channel 2, I hear it on the right speaker.
That dry signal comes with a very high latency, it´s like I have a delay effect with one repeat all the time. Pretty annoying.
When I use a DAW, Cubase, Amplitube 4, S-Gear or whatever, I listen the processed sound coming from the DAW, but the dry delayed signal too, no matter if the direct monitor it´s off in Cubase, for example.
I used many interfaces in the past, never happened something like that to me. First time.
Anyone knows that issue of have a solution? The drivers are actualized to the latest version.