I have ASUS ROG M16 with 165hz display refresh rate but whenever the sleep is on and i turn it back on it reverts to 60hz even plugged in.
I have to manually do it in display settings every time to make it 165 hz again.
Could you please tell me the full model name of the laptop you are using?
As for your question, have you tried to reinstall the graphics card driver?
How to find Model Name
[Notebook/AIO] Troubleshooting - Main (Internal) Display problem