samsung sm-g900a android 6.0.1 running 15.5.345.633 does not reliably ring anymore unless the app is in focus. you guys have put a lot of effort in the past year to remedy this problem. i'm not sure what's going on but this version seems to have reverted. i have another galaxy s8 with the latest updated running the same 3cx client and now the ringing has also become unreliable where it sometimes rings when sleeping and sometimes does not. i read the posts, the only suggestion that i found was battery savings mode which i've disabled for the app and then for the entire device and it did not make any difference. any recommendations?