MiniUpnp not working

I am running Miniupnp on my turris omnia. I think I correclty configured it, as it used to work some months ago, however now no ports are enabled/forwarded.
In particular, I am trying to forward some rules from a Synology NAS, but when it tries to forward, nothing changes on miniupnp side.

On logs side it seems to be everything ok:

user@turrisOmnia:~# cat /var/log/messages | grep miniupnp
Feb  4 19:00:52 turrisOmnia ucitrack: Setting up /etc/config/firewall reload dependency on /etc/config/miniupnpd
Feb  4 19:26:27 turrisOmnia miniupnpd[15259]: HTTP listening on port 5000
Feb  4 19:26:27 turrisOmnia miniupnpd[15259]: HTTP IPv6 address given to control points : [fd8e:11aa:870e::1]
Feb  4 19:26:27 turrisOmnia miniupnpd[15259]: Listening for NAT-PMP/PCP traffic on port 5351
Feb  4 19:26:47 turrisOmnia miniupnpd[15259]: /index.asp not found, responding ERROR 404

The configuration file is correct as well

user@turrisOmnia:~# cat /var/etc/miniupnpd.conf
ext_ifname=pppoe-wan
ext_ifname6=
listening_ip=br-lan
enable_natpmp=yes
enable_upnp=yes
secure_mode=yes
system_uptime=yes
force_igd_desc_v1=no
ext_perform_stun=no
ipv6_disable=no
bitrate_down=83886080
bitrate_up=41943040
lease_file=/var/run/miniupnpd.leases
notify_interval=30
clean_ruleset_threshold=20
clean_ruleset_interval=600
port=5000

I don’t have any idea how to move forward to make things working again, could it be an update that ruined something?