Hyper-V 2012, cannot get DHCP addresses on VM guests using external switch 2

I can't seem to get dhcp addresses on the guests using a 2nd external switch I made.  Each external VM switch is on a different router with DHCP.  Both switches get an IP addresses from routers, and I can ping both from core console.  Both switches are configured the same (external/share with host/no vlan). Guests work fine if I put them on switch 1. However when I use 2 the guests will not get an IP.  The working switch is a Broadcom NetExtreme 57 connecting to a Uverse gateway/modem. The non-working switch is an Intel pro/1000 MT Desktop connectling to a low-end Belkin router.  

Here is what I tried...

assigned a static IP...still no connection or packet flow

tested DHCP on router on other devices...works, range is 192.168.2.4 thru 2.98

tried unchecking share with host option in hyper-v manager...no difference

tried using vlans option in manager...no difference

tried uninstalling and reinstalling the guest network adapter...nothing (remember it will work on switch 1 anyway)

This setup works in Server 2012 with Hyper-V installed.  However now I am using Hyper-V core 2012.