I'm on my second LG G4 (I had new/off the shelf model, now I have a refurbished model from VZW). The WiFi at home is terrible (Asus RT-AC68U and Arris SB6141)... Doesn't matter if I have IPV6 on/off, connect to 2.4g or 5g, have 2.4g and 5g on same/separate SSIDs, dumb down the router settings, dumb down the phone (factory reset/minimal apps). I've read tons of message board posts here and elsewhere, and I've found nothing meaningful sans the "Lollipop can't handle IPV6" theory (I tried switching IPV6 off... didn't work for me). I run a robust home network (file server, etc.) thus I'm not dealing with this issue without a good deal of understanding. I've tried countless configs on the router and phone, and come up with bupkis. I've come to the conclusion that the firmware x hardware, or either on their own, are simply "broken" and I should throw in the towel and start looking for a new device/carrier.
Xfinity / Comcast: Blast 150
Mobile: LG G4 on Android 5.0.1 (13B / November 2015) (Config: As dumb as possible... OEM from factory reset/nothing added or removed)
Router: Asus RT-AC68U
Modem: Arris / Motorola SB6141
Help... From anyone with a good networking background (please no novice/average end-user responses). I can't believe a major carrier x major manufacturer would allow something like this to go unaddressed... Although it's beginning to seem that way. Thanks!