Galaxy S5 WiFi keeps dropping and reconnecting

Three days ago an AT&T update came through and I OK-d the installation. I have a Panasonic Home Network security app on the GalaxyS5 and it worked like a charm before the update. Now, it diconnects from the Home Network hub and I cannot reconnect unless I clear the cache restart and do all these conlicate steps. Now, my home security system is useless since I cannot control anything through my phone or look at the property when I am away.

Yes, I unchecked smart network switch and went through on everythig recommended on these three pages. Is there an AT&T patch to resolve the issue?

As I said, it did work perfectly before the AT&T update so I assume it is not a Samsung issue.

Galaxy s5 same problem. I was wondering why my data was 2 gb's over the limit. I couldn't figure it out, until this update for ATT came up today and wouldnt download because wifi wasn't connected. It looks like it's connected, but it isn't.

I have tried everything listed to correct it. Come on ATT, tell us the real fix.

Do I use mobile network for the new update, which eats a lot of data, but then the problem will be fixed?

@intergalaxy There has been an ongoing connectivity issue with the S5, which began with the 4.4.4 update.

In the solution posted by ATTMobilityCare, it was noted that Samsung and AT&T were working together to resolve the issue; however, the issue has never been resolved.  The only workaround that is known to prevent the phone's unintended usage of data is to uncheck the "Smart network switch" feature.  This does not prevent the constant scanning; however, it does prevent the phone from constantly and unnecessarily switching over to data while a perfectly good WiFi connection remains available.  Also, when "Smart network switch" is not enabled, connectivity is improved, not necessarily fixed, but it is improved. 

With "Smart network switch" unchecked, I usually have a good WiFi connection, but not always.  At least that keeps the phone from gobbling up data. Reverting back to 4.4.2 is not supported.  To the best of my knowledge, there is no fix in the offing and, given the phone's age, I have no reason to expect that status to change.   

Sometimes, even though everything indicates that I have a strong connection, the phone just will not connect to the internet.  This happens even when the phone is only inches away from my laptop that easily connects to the same WiFi network as do other wireless devices in my home.  I have a tablet, an ereader, an Amazon Echo and a Dot, none of which have a problem connecting to my WiFi network. This is definitely a Samsung issue. 

I have noted a number of complaints regarding Samsung connectivity issues, complaints that are not exclusive to the S5.  Due to this issue, and others as well, such as but not limited to lagging updates, a problem that has been highly exacerbated by AT&T's delays in releasing updates, I have decided that the S5 will be my last Samsung phone.  In addition, I have no intention of purchasing another carrier branded phone. 

Yes ever since the marshmallow update my phone does this, I have tried everything nothing works ,,can i uninstall the marshmallow update and go back to lollipop it worked great.

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@Hayseed wrote:

Yes ever since the marshmallow update my phone does this, I have tried everything nothing works ,,can i uninstall the marshmallow update and go back to lollipop it worked great.

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No, uninstalling the Marshmallow update is not an option. 

My Samsung just started dropping the wi-fi today.  I am not getting any help on a fix.  I am beyond frustration.  One minute it works and the next minute it doesn't 😞