WDS Event 772 not PXE booting with Server 2016 and Gen 2 Hyper-V VM or Physical PC.

New to using WDS. I'm receiving this error when trying to PxE boot on both VM and physical: 

"PXE Network Boot using IPv4 (ESC to cancel)

Performing DHCP Negotiation.......

  Station IP address is 10.100.1.138

  Server IP address is 10.100.1.20

  NBP filename is boot\x64\wdsmgfw.efi

  NBP filesize is 0 Bytes

PXE-E23: Client received TFTP error from server."

WDS and DHCP are on the same server. Options 60, 66, and 67 are set. NetBIOS over TCP/IP is disabled on the WINS tab. WDS is standalone. Active Directory is not being used. This is not on a domain. Simple workgroup homelab. The file wdsmgfw.efi is in the RemoteInstall\Boot\x64 directory. It has a file size of 1MB (1,030 KB).

This is the error in the Event Log: 

Event 772 WDSServer: An error occurred while trying to create the UDP endpoint for WDSTFTP provider on interface 10.100.1.20:69. This can happen if the network interface was disabled or changed, or some other application is already using the port. The provider  will not be able to receive requests on this interface. 

I can connect to TFTP via the command line TFTP client and download the wdsmgfw.efi from the WDS share with no issues (\boot\x64\wdsmgfw.efi). If I put the IP address of the server in the TFTP CLI, it won't connect and download, however. I have to put the actual server name (Server01 for example) in order for TFTP to connect and download the file. I then tried editing option 66 from the server IP to the actual server name as it worked in the CLI, but still get the same error.

CLI TFTP using server IP Address:

C:\Users\Administrator\Desktop\test>tftp -i 10.100.1.20 get \boot\x64\wdsmgfw.efi
 Connect request failed

CLI TFTP using server name:

C:\Users\Administrator\Desktop\test>TFTP -i Server01 get \boot\x64\wdsmgfw.efi
Transfer successful: 1054616 bytes in 1 second(s), 1054616 bytes/s

I'm officially stumped and this is driving me crazy.

To make things even more confusing, even though I keep receiving this TFTP error, I see this in the event logs of WDS:

Event 4096 Deployment-Services-Diagnostics

The following client booted from PXE: 
Hardware Address: 00-15-5D-01-14-14
IP: 10.100.1.132
Device ID: {9D64189E-5C95-4E89-9113-B7A8B8EA98DC}
ClientArchitecture: 4
Prestaged: false

EDIT:

I created a Gen 1 hyper-v VM to try legacy boot, and I get the following errors:

PXE-T01: File not found PXE-E3B: TFTP error - file not found