DUO Security Proxy servers in HA configuration

Has anyone setup HA for the DUO Proxy servers? I don't believe I can use the Radius iApp due to the specific port per DUO application(s)? I can successfully create a radius server with a "direct" server connection association to a single node (DUO Auth Proxy). However, I've been unsuccessful at setting up a HA configuration to include a second DUO Auth Proxy server. I've tried the following manual configurations (both failed): 1. Updated the "direct" server connection to point to a VIP (instead of a node) whereas the VIP was associated to a pool of DUO Auth Proxy servers. Failed (no response from server) 2. Created a new radius server referencing the pool of DUO Auth Proxy servers (not direct server connection). Essentially removing the VIP. Same error as above. *** The pool I used has Priority Grouping to prioritize its local site DUO Auth Proxy server unless its unavailable, then do to the other datacenter for DUO Auth Proxy. I have not setup a persistence profile due to the priority grouping. But, I will try that today. Hoping someone has tried setting up DUO Proxy HA and can provide any helpful insight. Thank you in advance. ~Jeff