My Samsung E7 has charging issue

[AC Question]

Hi every one ..... can any one please tell me why issue was raised from my samsung E7

My phone can't display the charge icon and as well as charging percentage i.e When i keep my phone to charge at 30% my phone was not showing any charge icon and not either increasing in percentage of battery,... when i am try to restart my mobile then i can see the percentage of battery was increased...
Case2:
I am using battery doctor app so when it reached 100% then it was displaying battery percentage to 100% and then i can remove the charger..