C3700-100NAS Wifi Drops after about 3 weeks to a month.

So pretty much ever since I got this modem about every 3 weeks to a month the Wi-Fi (2.4G) quits working and drops every connection off it.  I moved some of my devices that support it to 5G and they all seemed to be OK this time.  The wired connections are fine as well.  This modem is great when it is working but this is annoying as I have connected devices like my thermostat that I sometimes need to access remotely and I never know when it is going to happen. 

I am thinking it is a firmware problem but alas there are no firmware updates available.   Especially since the 5G stayed up.   It doesn't have as many connections coming and going as the 2.4G.   The web interface is always up and connecting to it from my wired PC and rebooting fixes the problem every time. 

I have seen similar problems in the forum on other models but most are older posts.  The solution at the time seemed to be to dump the Negear firmware and use a third parts which I have done long ago but I thought we were past that by now.

Is anyone else experiencing a similar issue and/or found a solution?