RDK-B Emulator looses IP Address after startup

i have followed the steps in page RDK-B Emulator Users Guide and was able to setup a RDK-B Emulator.
compilation was done on a Ubuntu VM (on Windows host)  (we have compiled rdkb2019q2)
i installed oracle virtual box (version 6.0) on the windows host, and setup the RDK-B Emulator.
one thing that, i am missing today is the Wireless Adapter. 

i configured the 2 network adapters to 'Bridged mode' as indicated in the RDK-B Emulator Users Guide.
After booting the emulator, i am facing following issues:

1. the VM doesn't respond to keyboard inputs many times. we had to re-boot the emulator multiple times and only after this, the keyboard inputs are received.
    is this a known issue? - it seems to be a problem of 'Capture' behavior of Virtual box.

2. the VM on start, does a DHCP and gets the IP address (ipv4). using ifconfig, i can see that emulator has got an ip. i am able to do: $ping google.com at this point successfully.
    

    but it seems like emulator continues in the background to acquire an ipv6 address as well. our networks are configured to not support ipv6 today.
    i see a print on the console:
    RTnetlink answers: cannot assign requested address

     

    After this, the  ipv4 address (previously obtained) is lost and emulator is not able to reach internet anymore. ($ping google.com fails)
    is there a work-around for this? can we somehow disable ipv6 in the emulator?