5th user unable to connect

Description of problem:

When we hit 5 users on OpenBSD, we're unable to connect. "The secure gateway has rejected the connection attempt".

Version of ocserv used:

ocserv-1.0.1 and ocserv-1.1.0

Client used:

Anyconnect 4.8.03036, as well at latest version of anyconnect android app

Distributor of ocserv

OpenBSD

How reproducible:

Describe the steps to reproduce the issue:

5 simultaneous connections, They can be the same user, via radius or flat file.

Actual results:

Feb  1 16:46:41 hostname ocserv[55824]: main[user]:23.17.0.229:58685 failed authentication attempt for user 'dmoeser.admin'
Feb  1 16:46:41 hostname ocserv[52509]: worker: 23.17.0.229 failed cookie authentication attempt
Feb  1 16:46:41 hostname ocserv[60203]: sec-mod: temporarily closing session for user (session: Q9zH4z)
Feb  1 16:46:41 hostname ocserv[55824]: main[user]:23.17.0.229:58685 user disconnected (reason: unspecified, rx: 0, tx: 0)
Feb  1 16:46:41 hostname ocserv[55824]: main: tun.c:774: ??: Error destroying interface: Invalid argument
Feb  1 16:46:41 hostname ocserv[55824]: main:23.17.0.229:58686 user disconnected (reason: unspecified, rx: 0, tx: 0)

Feb  1 17:02:21 hostname ocserv[55221]: main: tun.c:362: ??: Error setting IPv4: Device not configured
Feb  1 17:02:21 hostname ocserv[55221]: main: tun.c:774: ??: Error destroying interface: Invalid argument
Feb  1 17:02:34 hostname ocserv[67639]: worker:  HTTP CONNECT /CSCOSSLC/tunnel
Feb  1 17:02:34 hostname ocserv[55221]: main: tun.c:362: ??: Error setting IPv4: Device not configured
Feb  1 17:02:34 hostname ocserv[55221]: main: tun.c:774: ??: Error destroying interface: Invalid argument

Shows in the log. It also iterates and creates tun4-255 before failing

Expected results:

5th connection is successful