I have a new 2019 MacBook Pro 16" on Catalina 10.15.5. I recently got it back from the shop - upper case replacement for bad keyboard that included replacing the battery as part of the repair. Now occasionally when plugged in the battery charge actually decreases. For instance last night I opened it, it was plugged in at 100%. I used it to make an email and print a few pages for 15 minutes and the charge actually decreased to 93%. The icon shows when plugged in.
What would cause this? Ideas?
Does anyone else have a MBP that decreases the battery charge while plugged?