warpgate: Hosts with Multi-Factor auth fail

I have one host using Duo’s PAM module to provide multi factor authentication and another using Jumpcloud for the same purpose. Through Warpgate it fails despite having the ~/.ssh/authorized_keys file configured properly.

Connection failed  Authentication failed
channel 0: protocol error: close rcvd twice

Here’s what the entire workflow looks like on the host using Duo:

ssh heywoodlh:arch-firewall.wireguard@warpgate.kube
heywoodlh:arch-firewall.wireguard@warpgate.kube's password:
 Warpgate  Selected target: arch-firewall.wireguard
 Warpgate  Host key ...
 Connection failed  Authentication failed
channel 0: protocol error: close rcvd twice
Connection to warpgate.kube closed.

And here’s what it looks like for the host with Jumpcloud (I changed the hostname in this output):

ssh heywoodlh:example-host@warpgate.kube
heywoodlh:example-host@warpgate.kube's password:
channel 0: protocol error: close rcvd twice
 Warpgate  Selected target: example-host
 Connection failed  Connection refused (os error 111)
Connection to warpgate.kube closed.

As a sanity check, it seems to work just fine with my other machines not using multi-factor auth:

ssh heywoodlh:boba.wireguard@warpgate.kube
heywoodlh:boba.wireguard@warpgate.kube's password:
 Warpgate  Selected target: boba.wireguard
 Warpgate  Host key ...
 ✓ Warpgate connected

Last login: Wed Apr 13 15:09:11 2022 from 10.50.50.38
[heywoodlh@boba ~]$