In order for us to provide better support, we need to see the log generated by Citra. This guide will walk you through how you can obtain the log file: How to Upload the Log File.
Turn off Battery Boost in GeForce Experience and make sure you have set Power management mode to either Adaptive or Prefer maximum performance in Nvidia Control Panel.
Client Version Nightly 1372 HEAD-35690e3
OpenGL Vendor NVIDIA Corporation
OpenGL Renderer GeForce 940MX/PCIe/SSE2
OpenGL Version 3.3.0
GPU Driver Version 382.64
Enable Hardware Renderer [x]
Enable Hardware Shader [x]
Hardware Shader, Accurate Multiplication [x]
Hardware Shader, Geometry Shaders null
Enable Shader JIT [x]
System Region 2
Here’s some issues I found with your log that might help.
You are running out of date drivers for your GPU. You need to install the most recent driver for your graphics card from NVIDIA’s website. https://www.nvidia.com/Download/index.aspx