I play Throne Kingdom at War and Vikings Clash of Clans. They load 75% then timeout looking for an internet connection when using mobile data. They load fine when wifi is on. It seems to lock after my Google play user name flashes. Ended up trading out for a new phone same model thinking it was a problem with the phone.
I just downloaded Samsung Max VPN. It finally corrected the issue. Developer was not helpful. I have unlimited data and tried connecting at 4g along with a dozen other things. VPN worked.