INTERNAL NETWORK INTERNET SHARING EXPIRATION

I have a nested virtualization situation, that is a hyperv machine in a hyperv machine, and the guest VM uses an internal virtual switch (PayNet) which shares internet connection with the host VM default network adapter.

The internal VM is able to see the internet but only for few hours (between 9 to 15 hours) and then expires! I have to unshare the internet connection and share again each time before connectivity is restored and the cycle goes on and on.

How can I configure my internal VM to access the internet through the host VM permanently?

The host VM default network adapter has the following configuration:

Ethernet adapter Ethernet:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft Hyper-V Network Adapter
   Physical Address. . . . . . . . . : 00-15-5D-43-3D-11
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::40af:361b:10d1:831d%8(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.0.50.11(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.252.0
   Default Gateway . . . . . . . . . : 10.0.48.1
   DHCPv6 IAID . . . . . . . . . . . : 50337117
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-22-FF-37-0A-00-15-5D-43-3D-11
   DNS Servers . . . . . . . . . . . : 10.0.48.5
                                       10.0.48.6
   NetBIOS over Tcpip. . . . . . . . : Enabled

And the guest VM (The internal VM) network adapter (PayNet) has the following configuration:

Ethernet adapter vEthernet (PayNet):

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Hyper-V Virtual Ethernet Adapter #8
   Physical Address. . . . . . . . . : 00-15-5D-32-0B-17
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::f001:dbfe:ab90:3a2b%23(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.137.1(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . :
   DHCPv6 IAID . . . . . . . . . . . : 587208029
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-22-FF-37-0A-00-15-5D-43-3D-11
   DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
                                       fec0:0:0:ffff::2%1
                                       fec0:0:0:ffff::3%1
   NetBIOS over Tcpip. . . . . . . . : Enabled