Why does the multitasking button keeps spamming?

[AC Question]

I've Samsung Prime 4g. All the time the multi tasking button keeps spamming and to stop that temp, I just restart my phone but after the restart it does the same thing after few hours. I tried factory reset, It helped me for a week but spamming started again.

Can you guys tell me whats the problem and how it can be fixed?
I wanna disable button function and I want to double press home key multi tasking thing. I Dont know if its possible or no.

 

[Golfdriver97]

Welcome to the forums. Did you get a recent system update?

 

[MuzamilFarooq]

I tried that but when I check for updates it says your device has been modified in an unauthorized way.

 

[Golfdriver97]

Did you root your device?

 

[MuzamilFarooq]

It was rooted by the factory. I bought the phone when I saw that the phone is rooted I went to them and asked that why is the phone rooted they said almost al the phones are now rooted