Yes, none of these apps are set for battery optimization, thanks for your reply. I'm afraid that it is going to be a little more complicated than that and I think Samsung is aware of the problem and does not: A, have a fix, or B, does not care. there are many people complaining of this problem. I have been looking for a solution for a bit now. Hopefully someone here can help. The fact that my Samsung S-4 works perfectly (at least on WiFi as I have no carrier service on my old phone) speaks volumes on the problem being in perhaps a software glitch in the newer S-8s, and S-9s. There are also some complaining of the problem in S-10s. This is why perhaps in the next few months, I will be studying whether the I phones would suit me better even though I would have to really be embarrassed to go in that direction.