Phone keeps alternating between Wi-Fi and data

[Phoneguy108]

Are you having issues when you press active key too? Mine started acting this week. A white screen pops up when I press it. I can't back out of it. I have to press home button then minutes later I get a message saying " it's not responding do I want to close it?"
Odd little thing but annoying bc I used to use it.

I have a different problem with the active key.
Even though I have my active key set to bypass the lock screen it won't do it for some reason.

 

[Raineman2010]

My Galaxy S5 just recently began doing a similar thing constantly flicking between wifi and mobile data. I've worked out that my SD card was corrupt and since I removed it, the flicking between wifi and mobile data has stopped.