Q: when my mac is charging,the battery percentage on the lock screen updates as the charge increases but the indicator on the home screen(after entering the password) doesnt update unless i put the mac to sleep and then wake it up. why is that?

When my mac is charging,the battery percentage on the lock screen updates as the charge increases but the indicator on the home screen (after entering the password) doesn't update unless i put the mac to sleep and then wake it up. Why is that??

Also the power adapter becomes realy hot to the extent that i need to keep it in front of the airconditioner. The apple service centre did some online test and said everything was okay. I am still not satisfied. Please help.