So I recently got this problem after dealing with Ubuntu as my first unix-based os.
After plugging my charger, battery status in top right corner is not changing, decreasing percentages. I checked my battery status from the terminal with the udevadm info --path command, the output is:
E: POWER_SUPPLY_STATUS=Charging
E: POWER_SUPPLY_CAPACITY=39
At the same time GUI shows this
A couple of minutes later the GUI starts showing the proper icon and status.
When I unplug the charger, it does the same thing but the other way around(first showing 'charging' and then switching back to normal).
Checked the port by monitoring with udevadm monitor, output occurs on both plugging and unplugging, everything seems fine.
Let me know if you come up with a way to solve this problem.
