Issue arose for me after an 11/5/20 security update. After trying most online recommendations short of factory reset and waiting over a month for a new update which didn't resolve the issue, I stumbled upon the solution for my phone. Reset network settings. I had to plug in network passwords again for several wifi networks, but my phone is finally back to normal and battery lasts 3 days again. [Problem would disappear if I switched to airplane mode and either turned wifi or wifi calling on...but not both. Oddly with both on the problem came back even in airplane mode. ] Open the Settings app on your Android. Scroll to and tap either "General management" or "System," depending on what device you have. ... Tap either "Reset" or "Reset options." Tap the words "Reset network settings." ... You'll have to confirm that you want to reset your network settings.
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