Not a VM issue, this is a Switch / Windows issue.

You have to configure the switch to allow the IP for this machine for the DHCP helper address. Contact your Network admin to complete this, then it will work.

Well routing is one thing, it's the ability of the switches to allow DHCP zones, so you can't spoof IP addresses. If you didn't do it, I don't see how you expect the DHCP to answer on the zone without the use of helper addresses, since that's what they are for.

If you turn the other DHCP server off, and bring up a machine. Release / Renew IP. What happens? It should get a time out, no DHCP available to service the request. If it gives you an IP, there is the culprit. Another DHCP is giving out an IP.

Either way it's a configuration problem with your Windows machine, not VM. The vSwitches don't block anything in or out by default. The only firewall is for the console on the ESX host itself (traffic directed at the ESX server). Other than that, it does no filter / NAT / Firewall.

Or make the IP static on the VM, and make it the same as the Physical server, that will verify what the problem is.