ES450 not establishing VPN tunnel

I have an ES450 running the following:
Radio Firmware: SWI9X15C_05.05.58.01 r27044 carmd-fwbuild1 2015/03/05 00:02:40
Radio Module type: MC7354
Radio Module Identified: VZW

I have a static public IP address from Verizon for this.

The issue is I am trying to get an IPSEC VPN tunnel built between this device and a Cisco ASA5520 which sits behind a router doing a static NAT, and no matter what I try I am getting a successful Phase 1, but ends up with a Phase 2 mismatch. I am using AES256 with SHA for this setup, and I have seen where with the older version of the client that SHA didn’t work right and identified as MD5 - trying to set the Cisco side to use MD5 does not fix the issue.

I have worked on this for a few days now, and am stumped - has anyone else installed a similar setup and found a way to make this work?

Thanks in advance!