Graphics running low while charging laptop

Started a few months ago. While I was watching netflix, for an example, if I'm watching only on battery,is ok, but if I plug the charger then the video starts to get on a kind of slow motion kind. only after a seconds after I plug. and if i remove, after a few seconds it gets back to normal. I did a research and saw a few people talking about the same problem while they plugged as well.
It's an Acer Aspire M5-583P / Intel Core i5-4200 cpu 1.60Ghz 2.30 Ghz / 64 bits x64

thanks guys!

Hi Kamaia,
Are your power options like this,(top performance)
if not give them a try

Roy

yes it is. the only different was that was on economy mode. but now I changed to this way. let me give a try on a video

seems to work. until now, charging and no slow motion video.

thank you so much!