Zyxel NBG6615 periodic WAN disconnects issues

Hi,
I´m having the same problem. i use a pppoe connection on WAN side but every hour i have to restart the router to get a new connection

Zyxel_Jerry said:

We have contacted you via private message. Please kindly check your message box.

My first Zyxel product and what a disappointment  I have the same thing happening to me.  I am also on a pppoe connection on WAN.  Never seen a product that does this...haha...this what I get for buying a budget product?  Send me a PM too Jerry...or do I have to call the Meeseeks for help?

I seem to have the same problem, connection drops for few seconds at a time in every 5 or so minutes. Connection type is DHCP and I have the 

Zyxel_Jerry said:

Dear Sir,

1.Please provide your network topology
2. After obtaining the IP at the beginning, the request to update the IP will be re-initiated within 1/2 time of the lease time.
  The log means "The request is a message sent to the DHCP server device upstream of the wan, and the DHCP server responds with an "ACK" ."
3.If you own the router above the NBG6615, you could extend your IP lease time.
4.About the connection drop issue, could you describe more details about it?

Best regards,
Jerry

I'm not sure what topology means, but here is the WAN page
It is set up in a router mode. Internet comes straight from the apartments plug via Ethernet cable to the router and from there to my computer (wired). If I connect my computer straight to the apartments Ethernet port there is no issue, so it must be some wrong setting or fault in the router. 

The connection 'lags' every 5 minutes or so, but doesn't drop completely. If I'm playing a game the ping suddenly raises from normal 10 ms to over 500 ms for just a few seconds. And sometimes if my computer has been on sleep mode it might drop the connection, but works again if I restart the router. Same issue happens with every device connected to the router (chromecast, tv, other computer)

I have similiar problem with the same configuration as above.