We started missing calls on both of our LG K10 phones after the Nougat update (firmware K42820f) when on WiFi calling and not plugged in to a charger. We rely on WiFi calling since the cell service is too weak in our home. After the Nougat update, both phones often do not ring for incoming calls after 20 minutes or so of sitting idle while not charging. It seems like doze mode is inhibiting WiFi calling.
I'm an electrical/software engineer and tried all sorts of geeky things with no luck. We have the T-Mobile Cellspot Wifi router, a strong signal, and fast cable Internet service. Changing advanced WiFi settings to 100 ms beacon and DTIM 1 did not help (changed it back to the default of DTIM 3).
In the phone's advanced WiFi options, WiFi is set to stay on with the screen off. I've tried Ignore Battery Optimizations on WiFi Calling, WiFi, and a bunch of other apps. I am not using Greenify or anything that would make doze mode more aggressive.
I made a Llamalab Automate program to wake the phones up every 5 minutes for 15 seconds, and that seems to help but it doesn't totally solve the problem.
I am pretty sure it is a firmware problem related to doze. I hope this post gets seen/forwarded to T-Mobile and LG engineering.
Best answer by tmo_chris
Thanks for trying that