DTLS does not work in vhost

Description of problem:

If "udp-port" not specified in config for both default and vhost, DTLS for vhost do not work. Workaround: specify "udp-port" in vhost. But in this case, an warning message is displayed:

...
warning: udp-port is ignored on $host virtual host
...

Version of ocserv used:

OpenConnect VPN Server 1.3.0

Client used:

OpenConnect version v9.01-3

Distributor of ocserv

AlmaLinux 9.4

How reproducible:

Describe the steps to reproduce the issue:

Set config in /etc/ocserv/ocserv.conf

# Global

tcp-port = 443
udp-port = 443

run-as-user = root
run-as-group = root

device = vpn
rate-limit-ms = 100

dtls-psk = true

chroot-dir = /var/lib/ocserv
socket-file = ocserv.sock
pid-file = /var/run/ocserv.pid

#--------------------------------------------------
# Default host

listen-host = 192.168.5.1

server-cert = server-cert.pem
server-key = server-key.pem

auth = "pam[gid-min=1000]"

ipv4-network = 192.168.1.0/24
route = 192.168.1.0/24

#--------------------------------------------------
[vhost:oc.local]

server-cert = server-cert.pem
server-key = server-key.pem

auth = "radius [config=radiusclient.conf,groupconfig=true]"

ipv4-network = 192.168.2.0/24
route = 192.168.2.0/24

#------------------------------

#udp-port = 443

Start server
Connect to server

Actual results:

Client-side message:

No DTLS address
Set up UDP failed; using SSL instead

Expected results:

Client-side message:

Established DTLS connection (using GnuTLS)

Additional tests:

Same as config described above, only "udp-port" value changes.

"udp-port" in global only. Results: vhost no DTLS; default DTLS; no warning; udp:443 socket in used.
"udp-port" both in global and in vhost. Results: vhost DTLS; default DTLS; warning message; udp:443 socket in used.
"udp-port" in vhost only. Results: vhost no DTLS; default no DTLS; warning message; udp:443 socket in not used.
"udp-port" in not specified. Results: vhost no DTLS; default no DTLS; no warnings; udp:443 socket in not used.