Check out "Wifi Analyzer"
Sweep left / right for various screens.
Following shots show me, seh, on a crowded channel and a free one. Note the signal improvement.
If I had to make a prediction - either coincident to your last update, or due to a network improvement in your last update that routers you're hitting don't like, that's what changed your battery response and is the root cause of your trouble.
MSM = mobile set modem, would include wifi as I recall.