Have you performed a power reset on the device since the update? Also, is the Power Protection setting turned on? The battery protection setting might be set to maximum, which stops the battery from charging to 100%. To fix this, go to Settings > Device Care > Battery and change the setting to Basic or Adaptive.
Update: paid better attention this morning and looked at % prior to unplugging. Phone was at 100%. Very shortly after unplugging, it dropped to 99%. That was 2 hr 14 min ago, and it's only down to 97%. Looks like all is well.
I'm on Adaptive charging, my phone reboots automatically every Sun, Tues, Thurs and Sat. I don't play any games on my phone. There was a period (I think before the previous to latest update) where this was happening, then the 1st May update (that came out end of April) got it back up to 100%. Now when I take it off the charger in the morning, it's at 99% again. May have the timing off, but I remember the behavior.
Not sure if my auto reboots are what you're referring to as power reset. If memory serves me correctly, I also did a cache clean after the latest May security update.
