VMware Horizon DUO auth issue using F5 big-ip APM

I’ve followed the instructions on the page below for adding DUO to our F5 for the Horizon View app (configured initially using the F5 Horizon View iapp)…

However, we have a DUO auth issue logging in with the browser and also with the View client.

With the browser the DUO auth step completes (session log shows that step is a success), but the
[Common/HorizonView_VDI.app/HorizonView_VDI_remote_desktop] fails to connect.

VDI-error-1

Clicking on it gets another login window which shows the apps after username, password and domain are entered.

On the thick client, after the username, password and domain are entered, a popup window asking for “Next Code” appears.

After entering a “1” there (usually this means “send me a DUO push” from what I understand), and error comes back saying, “A RADIUS challenge failure occurred.”

Has anyone seen this behavior before? Any idea what’s causing it? I’m doing the same thing to add DUO for our F5 VPN and it works fine.

Thanks!