New tablets lose internet connection after waking from sleep?

[mrstblr]

Hello all! I hope I can find a solution to this annoying problem. My mom bought both of us the same tablet for the holidays and they both have the same problem. Whenever I put my tablet to sleep, it loses internet connection. I've scoured the forums and tried everything to fix the problem but can't find a solution. Half the time the wifi bar will appear in the top right, but sometimes it doesn't appear. My SSID shows "saved and secure" under it, but it won't connect. When the wifi bar at the top IS there and I try to use the internet I get the error (on Google chrome) "DNS PROBE FINISHED NO INTERNET." I would find it hard to believe that both tablets have the exact same problem... so I'm lead to believe it's an issue with my router. All of our other electronics hook up to the wifi fine including our phones and laptops. The weird thing is the internet works fine on the tablets until you put them to sleep, but upon waking they have these issues. The internet works on them if I do a normal reset, but I don't want to have reset the device every time I want to use it.

Here's what I've tried already:
- Unplugging the router and modem for a while and turning them back on
- Changing the Wifi channel to a clear channel
- Messing with security settings
- Changing the connection from DHCP to a Static IP
- Resetting the router to factory settings and creating a new SSID
- Forgetting the SSID and putting it back in
- Making sure that "always" option is selected for leaving wifi on during sleep
- Turning on high-accuracy location services
- Factory resetting the tablet

I'm super frustrated so any advice or suggestions would be greatly appreciated! Thank you!

 

[Musing]

Who is the manufacturer and model number of the tablets in question?