Need help with my laptop's fps

[nikoz_mb41]

I have this laptop, for exactly an year now. Laptop--->( https://support.hp.com/au-en/product/HP-Pavilion-15-au100-Notebook-PC/12499208/document/c05336097 )
 i always have it pluged in when i play because if i dont my fps is around 11-45, but when i have it pluged in my fps is around 60-120, depending on the game.
Today as i was playing i had some fps drops, so i unpluged and repluged it (thats what i do everytime have fps drops and it works) but this time it turned completely off. As if it had an empty battery. When i turned it back on i noticed that the battery percentage was stuck to 49% and the notification was saying (pluged in, NOT charging). So i opened up the game to see my fps again and they were not stable. From 11 fps to 120 and back to 11. (btw thats what happens when i play with my laptop not charging)
Sorry for my bad english, please help me if you can!!!

[AskTJ]

Might have battery saver enabled. Disable that and choose any performance options to on.