Can't mute my transmit audio after activation of 2nd slice

Start SmartSDR 1. Receiving on 14.1, normal SSB transmit 2. Select new Panadapter on slice 2, set receiver on 15m , 21.275 on slice/pandadapter 2 3. Slice 1, select 15M, 21.275, select transmit on this slice 4. Slice 2, right click on speaker icon to mute audio 5. Transmit on slice 1 and I hear my own audio (delayed slightly) in phones 6. x out of slice 2 by clicking on the x at the top right of the slice 7. I still hear my own audio in the earphones with only panadapter/slice 1 up Can anyone else reproduce this?