@Grezpyb  I had been experimenting this problem the same as everyone I see here,  This delusioning problem made me update firmware,  change router location, because wifi gets frozen or you have wifi but not wan,  after realizing that the time it took to mess with me was almost the same and it worked a bit longer when it had been shut down I came to the idea that it could be a temperature problem on the antenna stage that handles considerable power. A little warmth is enough to have the router out of court and I disassembled it (it has 2 hidden screws behind 2 rubber soles and you need a knife to leverage) then cleaned both sinks that had dust and grease, You will notice it works well when teh board is naked, but the cover suffocates them and the router goes haywire. I decided to put it slanted on one of it's sides so air would circulate upwards due to the expelled heat and that would allow the sink to get colder.  It  is working well now, the next level would be to install a cooler or better of expand the sinks, but it's working by now just after placing it vertically.

@jrizk07 Wich room temperature is there?

@Kevin_Z   How in the world are you expecting people to post using the same router when the router is not working?.   The thread is old but I don't see you brought a solution to anyone in years.   A person that purchases a router is not pursuing to take part in discussion forums.   they just intend to have a fairly decent connection.  The company should invest more in heatsink and less in trolls pretending being IT support