display – MacBook Pro becomes terribly Slow When Using The Secondary GPU

Whenever mac starts to use the secondary GPU (AMD Radeon), such as graphical tasks or when I use a secondary display, It becomes terribly slow.

I can say that it must be a GPU problem because if I disable GPU switching from Battery preferences, it starts to become slower.

This problem occurred after the day I run a high-graphics game (CS:GO). Can this damage the GPU?

Are there any solutions that I can try?