RT87U and Qnap - Strange DLNA issues

[gombosc]

Hi
I have a strange issue - I have a Qnap NAS (TS251) with DLNA enabled connected to a Asus rt87u (fw 380.64). When I start the NAS, I can see the DLNA and I can connect from my devices (TV, phone, etc) to the DLNA from Qnap and play movies, music without any issue
After several hours, I cannot see my DLNA server anymore and I can not connect it . After a Qnap restart everything is fine again for several hours
I suspect an issue in the router related to the broadcasting DLNA server. The DLNA service on the router is disabled. Also if I enable it there is no difference
In the router logs, the only messages I can find are:

Jan 27 21:45:11 miniupnpd[691]: remove port mapping 8081 TCP because it has expired
Jan 27 21:45:11 miniupnpd[691]: remove port mapping 8083 TCP because it has expired
Jan 27 21:45:11 miniupnpd[691]: remove port mapping 8082 TCP because it has expired
Jan 27 21:45:11 miniupnpd[691]: remove port mapping 8080 TCP because it has expired

in the Port forwarding logs I see
TCP 8080 192.168.2.150 8080 0h 37m 29s NAT-PMP 8080 tcp
TCP 8082 192.168.2.150 443 0h 37m 29s NAT-PMP 8082 tcp
TCP 8083 192.168.2.150 80 0h 37m 29s NAT-PMP 8083 tcp
TCP 8081 192.168.2.150 8081 0h 37m 29s NAT-PMP 8081 tcp

However, the port forwarding is not enabled on router. I do not know if the messages in the logs are related to my issue
Any idee what can be the issue ?
Please help me fix this issues as it gets where annoying...
Thank you in advance

 

[gombosc]

It seems that I found a solution!
I enabled the following 2 options on LAN/IPTV
Enable multicast routing (IGMP Proxy)
Enable efficient multicast forwarding (IGMP Snooping)
I also enabled the option
Enable IGMP Snooping
in Wireless/professional/2,4 Ghz
and finally I manually assigned an IP on Qnap NAS-in DHCP Server
Works like a charm in last 2 days!

 

[sfx2000]

Probably don't need IGMP proxy, just the IGMP-Snoop Doggy Dogg option...