Update February 7 = Issue is resolved. Some settings in the DHCP scope that was causing I conflict. Suspect on boot from PXE. USB and PXE are now working on 2.1.1 OptiPlex 3090.
Looking to boot from USB on a OptiPlex 3090 for the purpose of imaging utilizing WINPE to our ITSM platform. I have verified that the same USB in a OptiPlex 3070 is successful in one time booting from the same USB to run the WINPE is successful, thus not a USB problem per-say. I have attempted to boot off of 2 OptiPlex 3090's without success. Both are running BIOS 2.1.1. I have disabled Secure Boot in the BIOS. It seems that the BIOS does not recognize or enable the USB. I have verified all the USB configuration settings in the BIOS are also enabled, both front and rear. There are settings in the 3090 in regards to legacy boot that have seen to have been deprecated on the 3090 BIOS.  The USB is exFAT with *.efi file. At this point I am unsure of the next steps to troubleshoot or configure correctly to make this work. 
OptiPlex 3090 boot USB BIOS