Why is my Galaxy S7 only connecting to my 5.0ghz wifi and dropping the 2.4ghz?

[Android Central Question]

The other two phones (iphone and Moto ZPlay) are not having this problem and are connected to the 2.4ghz connection. The Galaxy S7 just started this a few days ago. I have rebooted the router and the phone. Neither made a difference.

 

[B. Diddy]

Welcome to Android Central! Do your 2.4 GHz and 5 GHz networks have different SSIDs or the same? Make sure they're different.

 

[AnitaSpark]

My SSID's are named differently by having 2.4 in one name and 5.0 in the other name. They have been named this way since I got the router over one and a half years ago. This phone has been working just fine and connecting to the 2.4ghz band the whole time until a few days ago. Again, the other two phones we have in the household are connected to the 2.4ghz band as I type with no issues. It's just this Android that suddenly won't stay connected to the 2.4ghz band for no apparent reason.

 

[B. Diddy]

Ok, try wiping the system cache partition: https://support.t-mobile.com/docs/DOC-30240

 

[AnitaSpark]

I just tried wiping the system cache. When it booted back up, it chose to connect to the 5.0ghz. I forced it to connect to the 2.4ghz and it dropped it 20 seconds later and went back to the 5.0ghz again.

 

[B. Diddy]

Did this start after a recent system update?

Also, try Safe Mode as well, in case some 3rd party app is causing this: https://support.t-mobile.com/docs/DOC-28008

 

[AnitaSpark]

The last software update was on 4/20, so that has been a while. I've only been having this problem the last few days. I started in safe mode, switched to the 2.4ghz and it dropped and went right back to the 5.0ghz. I haven't installed any new apps in the last month or so either.

 

[B. Diddy]

Strange. Bluetooth can sometimes interfere with 2.4 GHz wi-fi, since it uses the same general frequency. Does the problem persist if you turn off Bluetooth? Or if you change the 2.4 GHz wi-fi channel in the router's settings?

 

[AnitaSpark]

I keep the bluetooth off. I only turn it on when in my car. I ran through different channels on the router and nothing helped. It still drops the 2.4ghz and goes back to the 5.0ghz. I even used a wifi analyzer to see where the most activity is and it's choosing channel 11 when I put it back on auto, which is the least congested area. This is so weird.

 

[B. Diddy]

Let's take a step back for a second -- is there a problem with connecting to the 5 GHz network? Is it too out of range where you normally use your phone? If your router is set to wireless AC (instead of N), I think that defaults to 5 GHz.

 

[AnitaSpark]

I can connect to the 5.0ghz in my house and there is only a problem with that in my detached garage of course, so I think it's working as it should. Typically, all three phones would use the 2.4ghz. Right now, the other two are choosing the 2.4ghz with no problem. The Android will not stay connected to the 2.4ghz regardless of where I am. I tried to connect in the garage yesterday and I couldn't get the 2.4 or the 5.0. The phones normally connect to the 2.4ghz in the garage with no issue. I looked at the router settings and the 2.4ghz is set to g,n. The 5.0ghz is set to a,n,ac. I've never messed with those settings though.

 

[B. Diddy]

Just for kicks, try changing the 5 GHz setting to N only, if possible.

 

[AnitaSpark]

I tried it, no difference, still won't stay connected to the 2.4ghz.

 

[B. Diddy]

Sorry, I'm pretty much out of ideas, except for doing a factory reset or reinstalling the firmware using Smart Switch: http://www.sammobile.com/forum/showthread.php?t=29914

 

[AnitaSpark]

I ended up performing a factory reset. The phone is now staying connected to the 2.4GHz wifi. Problem solved for now it seems. Thank you for all of your time and suggestions.