Apps not downloading or appearing

Hi There, This is what is happening when I try to download an app. (Have never had this issue before).

1)Click 'Get' on App

2)Click Install

3) Enter Apple Password and Sign In

4)Sign In Accepted

5) Little Circle Starts Turning

6)Immediately jumps back to main page ' Search' 'Discover' Suggested.....App download disappears.

Any advice would be greatly appreciated! Thanks :D