I'm having the same issue, but mine started when my OS updated to Android 6.0 in mid-June. My G3 (LG-D850) is on AT&T. Check your software version and see if yours also updated recently. If so, these issues might be fixed the next time your OS updates.
Additionally, although I've never been impressed with this phone's battery life, it seems like the latest update just causes my battery to drain so quickly that I find myself charging it a minimum of 2x daily. Is this happening for you?
I've searched the internet, and it seems that turning off bluetooth may mysteriously help. I tried it and it seems to have helped some.
Apparently part of the problem is all of the apps that are updating to keep up with the OS update. That doesn't seem to explain all of it, however. Deleting any unused apps and cleaning the cache could help, but, again, it probably won't get to the root of the problem.
Seems like the most realistic solution is to just hope that the next update fixes whatever is causing this problem. G4 users and G3 users on other networks whose phones updated before mine seem to have less problems now than they did immediately after the update. Hopefully this will be the case for us, too.
Meanwhile...I've resigned myself to swearing at my phone and begging my husband to pick up alcohol on his way home from work because I'm too phangry (phone angry--I've decided it's a thing) to drive to the store to get it myself.