I had my RE450 extender for 2 years.  It was working fine. Suddenly, in the last couple days, the 2.4 GHz channel showed "connected, no internet access" on all my devices (phones, tablet, etc), but the 5 GHz channel is working fine.  

I tried unplugging the extender, re-starting my connected devices, rebooting my router, but still the same.  I even reset the extender and it is still the same result ..... no internet access on the 2.4 GHz channel.

Please let me know what to do to get it fixed. 

Thanks