Samsung S7 and few other andriod devices not redirected in RDP session with MTP mode

Hi,

I need to have Samsung S7 to be redirected into the RDP session. 
When I connect my phone to my laptop (windows 7 / windows8) I see the phone in both MTP and PTP modes on the client end. However, when I create an RDP session to another Windows 7 machine, the phone is redirected only when it is set to PTP mode. The same device fails to redirect when in MTP mode (neither is it visible in the deviec manager on the remote machine)

Also, conversely, when connecting to Windows 20008R2 server OS via RDS, the device is only visible when in MTP mode and does not redirect when in PTP mode.
Is this behavior expected? is there any particular reason for this behavior?