XDP broken in kresd, since libknot 3.1

There are some problem for us to get reply from knot resolver after we use xdp. The details are shown below:

OS: Ubuntu 21.14
kernel: 5.13.0-35-generic
network card: Intel Corporation Ethernet Controller X710 for 10GbE SFP+ (driver i40e)
knot-resolver:5.5.0-cznic.1
knot:3.1.1-cznic.1

kresd.conf

-- SPDX-License-Identifier: CC0-1.0
-- vim:syntax=lua:set ts=4 sw=4:
-- Refer to manual: https://knot-resolver.readthedocs.org/en/stable/

-- Network interface configuration
net.listen('10.0.0.2', 53, { kind = 'xdp' })
--net.listen('10.0.0.2', 53, { kind = 'dns' })
--net.listen('127.0.0.1', 853, { kind = 'tls' })
--net.listen('127.0.0.1', 443, { kind = 'doh2' })
--net.listen('::1', 53, { kind = 'dns', freebind = true })
--net.listen('::1', 853, { kind = 'tls', freebind = true })
--net.listen('::1', 443, { kind = 'doh2' })

-- Load useful modules
modules = {
	'hints > iterate',  -- Allow loading /etc/hosts or custom root hints
	'stats',            -- Track internal statistics
	'predict',          -- Prefetch expiring/frequent records
}

-- Cache size
cache.size = 1024 * MB

kresd@service

# SPDX-License-Identifier: CC0-1.0
[Unit]
Description=Knot Resolver daemon
Documentation=man:kresd.systemd(7)
Documentation=man:kresd(8)
Wants=kres-cache-gc.service
Before=kres-cache-gc.service
Wants=network-online.target
After=network-online.target
Before=nss-lookup.target
Wants=nss-lookup.target

[Service]
Type=notify
Environment="SYSTEMD_INSTANCE=%i"
WorkingDirectory=/var/lib/knot-resolver
ExecStart=/usr/sbin/kresd -c /usr/lib/knot-resolver/distro-preconfig.lua -c /etc/knot-resolver/kresd.conf -n
ExecStopPost=/usr/bin/env rm -f "/run/knot-resolver/control/%i"
User=knot-resolver
Group=knot-resolver
CapabilityBoundingSet=CAP_NET_RAW CAP_NET_ADMIN CAP_SYS_ADMIN CAP_SYS_RESOURCE
AmbientCapabilities=CAP_NET_RAW CAP_NET_ADMIN CAP_SYS_ADMIN CAP_SYS_RESOURCE
TimeoutStopSec=10s
WatchdogSec=10s
Restart=on-abnormal
LimitNOFILE=524288
Slice=system-kresd.slice

[Install]
WantedBy=kresd.target

And after we start knot resolver through systemctl start kresd@1.service, and run dig @10.0.0.2 www.baidu.com, we cannot get reply from knot resolver

root@master-ubuntu1:~# systemctl status kresd@1.service
● kresd@1.service - Knot Resolver daemon
     Loaded: loaded (/lib/systemd/system/kresd@.service; disabled; vendor preset: enabled)
     Active: active (running) since Tue 2022-03-22 14:32:34 CST; 4s ago
       Docs: man:kresd.systemd(7)
             man:kresd(8)
   Main PID: 17028 (kresd)
      Tasks: 1 (limit: 629145)
     Memory: 21.2M
        CPU: 106ms
     CGroup: /system.slice/system-kresd.slice/kresd@1.service
             └─17028 /usr/sbin/kresd -c /usr/lib/knot-resolver/distro-preconfig.lua -c /etc/knot-resolver/kresd.conf -n

3月 22 14:32:34 master-ubuntu1 systemd[1]: Starting Knot Resolver daemon...
3月 22 14:32:34 master-ubuntu1 kresd[17028]: libbpf: Kernel error message: XDP program already attached
3月 22 14:32:34 master-ubuntu1 systemd[1]: Started Knot Resolver daemon.

root@master-ubuntu1:~# dig @10.0.0.2 www.baidu.com

; <<>> DiG 9.16.15-Ubuntu <<>> @10.0.0.2 www.baidu.com
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached