a6100 connects but says "no internet" with 5g...but works fine with 2.4 g

[bigjwig]

Worked fine with windows 7 for last year. Upgraded to windows 10 and it will connect (first part of diagram says connected - but says no internet (second part diagram has red X. Only does this for 5 g connection. When I connect 2.4 g it works fine. Problem is the 5 g is twice as fast !! Then every once in a while it will connect at 5 g. (But rare)  Any ideas on what to check??

[lbjailer]

I'm having the same issue. It connects to 2G but 5G altghough shows up says no internet connection. I'm using AT&T Gigabit service on a Pace 5268 AC Residential Gateway.